JP5648787B2 - Air spring - Google Patents

Description

  The present invention relates to a rolling seal type air spring as a vertical seismic isolation device for isolating and supporting a structure such as a building against vertical vibrations.

As this type of air spring, those shown in Patent Documents 1 and 2 are well known.
This is a structure in which a diaphragm made of a cylindrical rubber film is arranged in an outer cylinder to define an air chamber, and an operating body (inner cylinder) is elastically supported in the vertical direction via the diaphragm. By interposing this air spring between the foundation of the building and the superstructure, the vertical vibration of the superstructure is absorbed by the diaphragm, and an excellent seismic isolation effect is obtained, and a high level of seismic performance is required. It is suitable as a vertical seismic isolation device for buildings in nuclear power generation facilities and the like.

  This type of rolling seal type air spring itself has been generally used as a vibration isolator for railway vehicles. However, a rolling seal type air spring having a general structure has been used as a seismic isolation device for large buildings. If an attempt is made to support a heavy object, the diameter of the air spring becomes very large, resulting in an increase in cost, and a large number of air springs are required, so that it may be difficult to arrange in a plane.

  Therefore, when using this type of rolling seal type air spring to achieve the vertical isolation of a heavy building, it is necessary to make it sufficiently small and strong enough to be used with high pressure. Therefore, in the air spring disclosed in Patent Document 2, the diaphragm is bias-reinforced with a reinforcing fiber, the roll diameter of the diaphragm (gap between the outer cylinder and the working body), or the initial gap between the outer cylinder and the diaphragm. Is appropriately set in relation to the film thickness of the diaphragm, thereby reducing the size and increasing the strength.

JP 2005-16633 A JP 2006-342940 A

The air spring shown in Patent Document 2 can be used as a vertical seismic isolation device for a structure such as a building by means of the above-described miniaturization and high strength. It is a little complicated, especially in order to define a completely airtight air chamber by incorporating a diaphragm in the outer cylinder, it requires a complicated seal structure and a complicated assembly process therefor. For this reason, there is a limit to downsizing and cost reduction, and it is not necessarily perfect in terms of maintainability, durability, and reliability.
Accordingly, while the effectiveness of the air spring shown in Patent Document 2 is recognized, there is still room for further improvement in terms of the above points, and in order to widely disseminate it as a seismic isolation device applied to nuclear power generation facilities and the like. There is a need for further improvements in that regard.

  In view of the above circumstances, the present invention realizes further simplification of this type of air spring, thereby facilitating its manufacture and sufficiently reducing the size and cost, further improving maintainability, durability, and reliability. An object is to provide an effective air spring that can be improved.

The invention according to claim 1 is a rolling seal type air spring for isolating and supporting a structure such as a building against vibrations in the vertical direction, and has an inner diameter smaller than that of the outer cylinder. A cylinder is disposed so as to be relatively displaceable in the vertical direction, a diaphragm made of a mortar-shaped or cylindrical rubber film is disposed in an annular gap between the outer cylinder and the inner cylinder, and the diaphragm is An air chamber is defined by sealing one end and the other end of the gap in an airtight manner with respect to the outer cylinder and the inner cylinder, respectively, in a state in which the gap is elastically inverted in the vertical direction. A bead portion for fastening to the outer cylinder is formed at one end of the diaphragm corresponding to the diameter of the outer cylinder, and a bead portion for fastening to the inner cylinder at the other end of the diaphragm Is formed to correspond to the diameter of the inner cylinder, The bead portion at the end is formed in a flange shape that bulges outward, the bead portion at the other end portion of the small diameter is formed in a flange shape that bulges inward, and each bead portion is connected to the outer cylinder and the Ri Na and fastened rumored hermetically respectively the inner cylinder, and wherein the Rukoto such to provide a plurality of stiffening ribs radially outward of the outer cylinder.

  According to a second aspect of the present invention, in the air spring of the first aspect, a bead wire made of a metal wire or a bead portion reinforcing member of a metal ring is embedded in the bead portion, and the thickness of the bead portion reinforcing member is set. Is set to 30% or more of the total thickness of the bead portion, and the fastening allowance of the bead portion by the fastener is set to 20% or more of the total thickness of the bead portion.

  According to a third aspect of the present invention, in the air spring according to the first or second aspect, the annular gap between the outer cylinder and the inner cylinder is set to be not less than 3 times and less than 10 times the film thickness of the diaphragm. It is characterized by being set in the range of

  According to a fourth aspect of the present invention, in the air spring according to the first, second, or third aspect, bias reinforcing fibers inclined with respect to the circumferential direction of the diaphragm are embedded in the peripheral surface of the diaphragm. It is characterized by.

  According to a fifth aspect of the present invention, in the air spring according to the first, second, third or fourth aspect of the present invention, the air space defined by the diaphragm is communicated with an internal space of the inner cylinder as an auxiliary tank via an orifice. It is characterized by being damped.

According to the air spring of the first aspect of the invention, it is possible not only to exhibit an excellent seismic isolation effect against vertical vibration in the same manner as this type of conventional air spring, but also of the bead portion formed above and below the diaphragm. The diameter is made different from that of the outer cylinder and the inner cylinder, and the bead portion at one end of the large diameter is formed in a flange shape that bulges outward, and the bead portion at the other end of the small diameter is inward. By forming the bulging flange shape and fastening the bead portion to the outer cylinder and the inner cylinder with fastening metal fittings, the overall structure can be improved compared to a conventional general air spring of this type. It can be greatly simplified, thus not only simplifying the assembly process but also simplifying parts and reducing the number of parts, thereby reducing costs, improving maintainability, durability, and reliability. Plan Can.
Moreover, the pressure resistance performance of an outer cylinder can be improved more by providing several stiffening ribs radially on the outer side of an outer cylinder.

  According to the air spring of the second aspect of the invention, the bead portion is provided with a bead wire reinforcing member made of a metal wire or a metal ring, and the thickness thereof is set to 30% or more of the thickness of the entire bead portion, In addition, by setting the tightening allowance of the bead portion with the fastening bracket to 20% or more of the thickness of the entire bead portion, sufficient sealing performance can be ensured only by tightening and fixing with the fastening bracket regardless of the self-sealing structure.

  According to the air spring of the third aspect of the invention, the pressure resistance of the diaphragm is improved by setting the annular gap between the outer cylinder and the inner cylinder to be not less than 3 times and less than 10 times the film thickness of the diaphragm. A pressure-resistant performance of 10 MPa or more can be expected, and in particular, a high-pressure specification that can be effectively applied as a base-isolating support for a heavy structure such as a building in a nuclear power generation facility can be achieved.

  According to the air spring of the present invention, the pressure resistance can be sufficiently improved by embedding various reinforcing fibers in the peripheral surface of the diaphragm, and the direction of the reinforcing fiber is particularly set in the circumferential direction of the diaphragm. By making the bias reinforcement inclined with respect to the angle, it is possible to improve the pressure resistance performance without hindering the smooth stretching movement in the vertical direction by appropriately adjusting the intersection angle of the bias reinforcing fibers.

  According to the air spring of the fifth aspect of the present invention, the inner cylinder is used as an auxiliary tank to communicate with the air chamber defined by the diaphragm, and the orifice is provided at the communication portion between the inner cylinder and the air chamber. It is possible to provide an attenuation function due to pressure loss of the air flow passing therethrough.

It is sectional drawing which shows schematic structure of the air spring which is embodiment of this invention. It is sectional drawing which shows a diaphragm similarly.

FIG. 1 shows an embodiment of an air spring of the present invention. This is basically the same as the conventional air spring disclosed in Patent Document 2, with the outer cylinder 1, the inner cylinder 2 (corresponding to the working body in the conventional air spring) and the diaphragm 3 as the constituent elements. Is installed between the upper structure and the upper structure and functions as a vertical seismic isolation device.
However, in contrast to the conventional one in which the outer cylinder 1 is fixed upward with respect to the foundation and the operating body is fixed with respect to the superstructure, in this embodiment, the top and bottom are reversed. The outer cylinder 1 is fixed downward with respect to the upper structure, and the inner cylinder 2 is fixed with respect to the foundation.

  The diaphragm 3 in the air spring of the present embodiment is made of a mortar-shaped or cylindrical rubber film, and is vertically moved in an annular gap 4 between the outer cylinder 1 and the inner cylinder 2 as shown in FIG. The diaphragm 3 is arranged in an elastically inverted state, and its both end portions are sealed in an airtight manner with respect to the outer cylinder 1 and the inner cylinder 2, respectively. The bead portions 3a and 3b are formed at both ends, respectively.

That is, as shown in FIG. 2, at one end (upper end) of the diaphragm 3, a bead portion 3a for fastening to the outer tube 1 is set to a size that matches the diameter of the outer tube 1 and outward. It is formed in a flange shape that bulges.
On the other hand, the other end portion (lower end portion) of the diaphragm 3 has a bead portion 3b for fastening to the inner cylinder 2 in a flange shape that is sized to match the diameter of the inner cylinder 3 and bulges inward. Is formed.
In other words, the diaphragm 3 in the air spring of the present embodiment has the diameters a and b of the bead portions 3a and 3b formed above and below the different diameters corresponding to the difference in diameter between the outer cylinder 1 and the inner cylinder 2. The diameter a of the upper end bead portion 3 a fastened to the outer cylinder 1 is made slightly larger than the effective diameter of the upper periphery of the diaphragm 3, and the lower end bead portion 3 b fastened to the inner cylinder 2. The diameter b is smaller than that.

In the conventional general air spring, as shown in Patent Documents 1 and 2, the beads 3a and 3b are assembled to the outer cylinder and the operating body (corresponding to the inner cylinder) as a so-called self-sealing structure. However, in the air spring of the present embodiment, instead of using such a complicated self-sealing structure, each bead portion 3a, 3b is connected to the outer cylinder 1 and the inner cylinder 2 by the fastening metal 6a, 6b is directly tightened and fixed so that the sealing structure can be simplified and the sealing performance can be surely ensured to define the air chamber 5 in a completely airtight state. ing.
In this embodiment, the upper end of the outer cylinder 1 is an open end, and the flange portion 1a is integrally formed around the outer end. Therefore, the above-mentioned fastening metal fitting 6a is formed in a disc shape and is attached to the flange portion 1a. On the other hand, the bead portion 3a is sandwiched while also serving as an upper surface plate for closing the open end of the outer cylinder 1 by being fastened. However, the fastening fitting 6a is not limited to such a configuration, and any suitable fastening fitting may be employed as long as the bead portion 3a can be fastened and fixed to the outer cylinder 1 to be fastened in an airtight manner. In addition, an appropriate upper surface plate may be further fastened to the open end of the outer cylinder 1.
In this embodiment, as will be described later, the upper end of the inner cylinder 2 is closed by the upper surface plate 2a so as to function as the auxiliary tank 8, and the orifice 9 is formed there. 6b is also a disk having the same orifice and is fastened to the upper surface plate 2a so as to sandwich the bead portion 3b. However, the fastening bracket 6b is not limited to such a configuration. As long as the bead portion 3b can be fastened to the inner cylinder 2 and fastened in an airtight manner, an appropriate one may be used.

  Based on the above configuration, the air spring of this embodiment has different diameters a and b of the bead portions 3a and 3b formed on the upper and lower sides of the diaphragm 3 in correspondence with the diameters of the outer cylinder 1 and the inner cylinder 2. The large diameter upper end bead portion 3a is formed in a flange shape bulging outward, the small diameter lower end bead portion 3b is formed in a flange shape bulging inward, and the bead portions 3a, 3b are By adopting a configuration in which the fastening fittings 6a and 6b are simply clamped and fixed to the outer cylinder 1 and the inner cylinder 2, an excellent seismic isolation effect against vertical vibrations can be exhibited in the same manner as this type of conventional air spring. Of course, the overall structure can be greatly simplified compared to the conventional air springs shown in Patent Document 1 and Patent Document 2, and therefore the assembly process can be simplified, as well as the simplification of the parts and the parts. Reduce points DOO are possible, it by cost, maintenance and durability, is capable of improving the reliability.

  Although the basic embodiment of the air spring of the present invention has been described above, the present invention can be appropriately applied and modified as described below, for example, as necessary in addition to the above-described configuration.

  The bead portions 3a and 3b are preferably provided with a bead portion reinforcing member 7 such as a bead wire made of a metal wire or a metal ring. In that case, the thickness of the bead portion reinforcing member 7 is set to 30% or more of the thickness of the bead portion 3a or the bead portion 3b, and the tightening margin of the tightening portion by the fastening fittings 6a and 6b is 20 of the thickness of the bead portions 3a and 3b. Preferably, the tightening rate can be 30% or more, and the sealing performance there can be ensured sufficiently and reliably.

The size of the annular gap 4 (d dimension in FIG. 1) between the outer cylinder 1 and the inner cylinder 2 can be appropriately set in relation to the film thickness of the diaphragm 3 (t dimension shown in FIG. 2). In particular, in order to improve the pressure resistance performance of the diaphragm 3 and make it a high pressure specification, when the dimension d of the gap 4 is not less than 3 times and less than 10 times the film thickness t, that is, the ratio thereof is α = d / t. It is preferable to set in the range of 3 ≦ α <10.
In the case of an air spring as a general vibration isolator for a vehicle, the ratio α is set to 10 or more, so the pressure resistance performance is limited to about 2 to 3 MPa. It is known that if it is about 5, the pressure resistance will be improved to about 5.6 MPa, if α is about 5, it will be improved to about 8 MPa, and if α is about 3, it can be expected that pressure resistance of 10 MPa or more can be expected. Therefore, it is possible to achieve a high-pressure specification that can be effectively applied to a heavy structure such as a building in a nuclear power generation facility.
In addition, although the equivalent knowledge is acquired also in patent document 2, the outer diameter of the diaphragm used for the pressure | voltage resistant test of patent document 2 is as small as 243 mm, and the outer diameter of the diaphragm used by the present inventors' research Is as large as 600 mm, and the relationship between the pressure resistance performance and the gap 4 between the outer cylinder 1 and the inner cylinder 2 is confirmed even for a large diaphragm.

  In order to improve the pressure resistance performance of the diaphragm 3, it is also preferable to embed various reinforcing fibers, for example, a plurality of layers of interdigital cords, on the peripheral surface of the diaphragm 3, and in particular, the direction of the reinforcing fibers with respect to the circumferential direction of the diaphragm Inclined bias reinforcement is preferable, and in that case, by appropriately adjusting the intersection angle of the bias reinforcing fibers, it is possible to improve the pressure resistance performance without hindering smooth stretching movement in the vertical direction.

  When the rigidity of the air spring of the present invention is set low, it is preferable that the inner cylinder 2 is used as the auxiliary tank 8 to communicate with the air chamber 5 defined by the diaphragm 3. By providing the orifice 9 at the communication portion between the air chamber 5 and the air chamber 5, it is possible to provide an attenuation function due to the pressure loss of the air flow passing therethrough.

  It is conceivable to provide a stiffening rib 10 on the outer side of the outer cylinder 1 as necessary, whereby the pressure resistance of the outer cylinder 1 can be further increased. In this case, for example, about 4 to 36 stiffening ribs 10 may be provided radially according to the required pressure resistance, and the height of the stiffening ribs 10 may be about 1 to 5 times the wall thickness.

  It should be noted that a three-dimensional seismic isolation device as shown in Patent Document 1 can be configured by integrally providing horizontal seismic isolation means such as laminated rubber on the upper or lower portion of the air spring of the present invention. In that case, like the air spring shown in Patent Document 1, the inner cylinder 2 is combined so as to be slidable in the vertical direction with respect to the outer cylinder 1 so as to restrain the horizontal relative displacement between them. What is necessary is just to comprise.

  Further, as described above, in the above embodiment, the inner cylinder 2 is fixed to the base and the outer cylinder 1 is fixed to the upper structure. Of course, it can be used in a state where the top and bottom are reversed (the outer cylinder 1 is fixed to the foundation and the inner cylinder 2 is fixed to the upper structure). In that case, the bead portion 3 a for fastening to the outer cylinder 1 is formed at the lower end portion of the diaphragm 3, and the bead portion 3 b for fastening to the inner tube 2 is formed at the upper end portion of the diaphragm 3. Become.

  Furthermore, it is realistic that the air spring of the present invention literally encloses air in the diaphragm 3 (and the auxiliary tank 8) and uses its elasticity. However, if it is necessary for special applications, it is necessary. For example, it does not preclude the use of various gases including inert gases and liquids including liquids instead of air or mixed with air (from this point of view, the air spring of the present invention is more Strictly speaking, it should be called a fluid spring).

DESCRIPTION OF SYMBOLS 1 Outer cylinder 1a Flange part 2 Inner cylinder 2a Top plate 3 Diaphragm 3a, 3b Bead part 4 Crevice 5 Air chamber 6a, 6b Fastening metal fitting 7 Bead part reinforcement member 8 Auxiliary tank 9 Orifice 10 Stiffening rib

Claims (5)

A rolling seal type air spring for supporting a structure such as a building in isolation from vertical vibrations,
An inner cylinder having a smaller diameter than the outer cylinder is disposed inside the outer cylinder so as to be relatively displaceable in the vertical direction, and a mortar-shaped or cylindrical rubber film is formed in an annular gap between the outer cylinder and the inner cylinder. The diaphragm is arranged, and the one end and the other end of the diaphragm are fastened to the outer cylinder and the inner cylinder in an airtight manner with the diaphragm elastically inverted vertically in the gap. To define an air chamber,
A bead portion for fastening to the outer cylinder at one end portion of the diaphragm is formed corresponding to the diameter of the outer cylinder, and for fastening to the inner cylinder at the other end portion of the diaphragm. The bead portion is formed corresponding to the diameter of the inner cylinder, the bead portion at one end of the large diameter is formed in a flange shape that bulges outward, and the bead portion at the other end of the small diameter bulges inward. is formed in a flange shape, Ri Na and fastened to each rumored hermetically to the outer cylinder and the inner cylinder by the respective bead portions of the fastening bracket,
Air springs, wherein Rukoto such to provide a plurality of stiffening ribs radially outward of the outer cylinder. The air spring according to claim 1,
A bead wire made of a metal wire or a bead portion reinforcing member of a metal ring is embedded in the bead portion, the thickness of the bead portion reinforcing member is set to 30% or more of the total thickness of the bead portion, and the fastening metal fitting is used. An air spring characterized in that a tightening margin of the bead portion is set to 20% or more of a thickness of the whole bead portion. The air spring according to claim 1 or 2,
An air spring characterized in that an annular gap between the outer cylinder and the inner cylinder is set in a range of 3 times or more and less than 10 times the film thickness of the diaphragm. The air spring according to claim 1, 2, or 3,
An air spring characterized in that bias reinforcing fibers inclined with respect to a circumferential direction of the diaphragm are embedded in a peripheral surface of the diaphragm. The air spring according to claim 1, 2, 3, or 4,
An air spring characterized in that an internal space of the inner cylinder is used as an auxiliary tank to communicate with an air chamber defined by the diaphragm via an orifice.

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