JP3710237B2 - Laminated rubber bearing with lead plug - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention is an energy absorber that is mounted between two members that are spaced apart from each other in the vertical direction and absorbs kinetic energy due to relative displacement between these two members, particularly for civil engineering buildings such as bridges, buildings, and houses. The present invention relates to a technology for protecting a superstructure from vibrations such as seismic vibrations by absorbing vibration energy such as seismic vibrations from the outside as plastic deformation energy of the material.
[0002]
[Prior art]
Conventionally, “laminated rubber bearings with lead plugs” as a vibration isolator is known, which uses shear deformation of laminated rubber to deform cylindrical lead plugs that are energy absorbers. is there. The lead plug is formed by opening a hole penetrating in the vertical direction in the central portion of a rubber laminate in which rubber and intermediate steel plates are alternately laminated, and enclosing the lead plug into the hole by pouring or press-fitting. The laminated body of rubber and intermediate steel plate is relatively hard in the vertical direction for the foundation and intermediate parts of civil engineering buildings, but has two degrees of freedom in the horizontal direction and is elastic to shear forces. It acts to allow various deformations. On the other hand, the lead plug as the energy absorbing material functions as a damper, and acts to suppress vibration by absorbing vibration energy in the shear direction. This type of “laminated rubber bearing with lead plug” is disclosed as “periodic shear energy absorber” in Japanese Patent Application Laid-Open No. 52-49609.
[0003]
When encapsulating lead plugs in the holes of the rubber laminate, the volume of the lead should be about several percent larger than the volume of the holes, and the intermediate steel sheet will bite into the lead by applying pressure to the lead plugs. Interlocking is an important factor for exhibiting the damping effect due to plastic deformation of lead.
The “lead plug-containing laminated rubber bearing” constructed in this way functions as a stable energy absorbing material within a relatively small range of several tens of percent of shear strain, but the magnitude of shear strain is +/−. About 100% is the limit, and if a large shear strain is applied forcibly, the lead plug cracks during repeated deformation and breaks, resulting in a loss of energy absorption capability. The rubber itself can be deformed to a shear strain of 400% or more, but the metal lead can not withstand such a large shear strain and gradually enters the soft rubber layer to become a shape that is far from the initial shape and breaks. It ’s all over. In order to prevent this, the number of intermediate steel plates is increased to about 20 to 40.
[0004]
In order to deal with the problem of cracking or loss of energy absorption capability while the lead plug is repeatedly deformed, Japanese Patent Application Laid-Open No. 59-62742 discloses an “energy absorption device”, Japanese Patent Application Laid-Open No. 61-176676. In the “periodic shear energy absorbing device” disclosed in Japanese Patent Publication No. Hokukai, it is proposed to provide a restraining means composed of a flexible wall that allows deformation of the lead plug around the lead plug. However, these restraining means are made of a band material spirally wound around the lead plug, and it is difficult to cope with the case where the shear strain is very large.
[0005]
On the other hand, instead of inserting the lead plug into the rubber laminate, the lead plug alone is used as a damper by utilizing the energy absorption effect by plastic deformation of the lead itself. In this case as well, a reinforcing material is embedded inside to prevent breakage due to plastic deformation of lead (Japanese Patent Laid-Open No. 61-290245), or the surface is covered with a spiral wire (Japanese Patent Laid-Open No. 61-294230). No.), the outer circumference is covered with a steel ring that restricts the relative movement in the radial direction (Japanese Patent Laid-Open No. Sho 61-294232), and the outer circumference is closely attached with a plurality of steel body rings (specialized) Japanese Laid-Open Patent Publication No. 61-294234), and it has been proposed to wrap a steel strip having an S-shaped outer periphery in a spiral shape (Japanese Patent Laid-Open No. 62-274124). However, none of them has prevented lead from being broken for a long period of time, and has remained at a level where a slight life-prolonging effect is obtained.
[0006]
[Problems to be solved by the invention]
This invention makes it a subject to solve said problem regarding the conventional "lead plug containing laminated rubber bearing".
That is, the present invention (1) prevents the penetration of lead into the rubber layer in order to improve the shear deformation ability of lead to 200% or more by making the shear deformation of the rubber layer, and thereby ( The present invention provides a laminated rubber bearing with a lead plug for the purpose of 3) improving the Dan Pink performance and (4) preventing the breakage of lead.
[0007]
[Means for Solving the Problems]
In order to achieve such a problem, in the present invention, a laminated rubber portion formed by alternately laminating rubber and an intermediate steel plate in the vertical direction, and a hole provided through the laminated rubber portion in the vertical direction. A lead plug-containing laminated rubber that absorbs the kinetic energy between two vertically spaced members, comprising an inserted elastoplastic material made of lead and a restraining portion provided around the elastoplastic material. In the support, the restraining portion has a structure in which a plurality of enclosure plates made of a material having a yield stress equal to or higher than lead and having openings defining the holes are vertically stacked, and the enclosure plates are adjacent to the enclosure plates. Between the intermediate steel plate and the intermediate steel plate so as to be mechanically interlocked with the intermediate steel plate at the time of the shear deformation. Kept in place And at least some of the surrounding plates are formed integrally with the intermediate steel plate. A laminated rubber bearing with a lead plug is provided.
[0008]
When the laminated rubber bearing with the lead plug of the present invention is subjected to shear deformation, the laminated rubber portion is elastically deformed, while the lead elastic-plastic member is plastically deformed. In that case, since the shroud is disposed in a positional relationship with the intermediate steel plate so as to be mechanically interlocked with the intermediate steel plate, the lead elastic-plastic member is also uniform in the shear direction together with the laminated rubber portion. Causes deformation. The shroud that constitutes the restraining part has an overlap margin even when the sliding part has a predetermined shear deformation, so even if the shear strain becomes a large value close to a predetermined value, the containment effect of lead is sufficient In addition, since the constraining portion is a laminated structure of a large number of surrounding plates, a large number of contact points with the lead elastic-plastic member can be taken in the vertical direction, and energy absorption efficiency (SED) can be obtained as described later. Can be bigger. Therefore, there is little slip between the enclosure plate and the surface of the lead elastic-plastic member, and the deformed lead elastic-plastic member is restored to its original shape by utilizing the elastic restoring force of the elastically deformed laminated rubber part. Is possible. “Having an overlap allowance even at a predetermined shear deformation” means that even when the shear strain reaches 250%, the enclosure is overlapped with the adjacent enclosure so that the lead elastic-plastic member is contained. It is in a state where they are in contact with each other.
[0009]
Further, the present invention is characterized in that the enclosure plate and the intermediate steel plate are formed integrally or with a slight gap therebetween. As a result, mechanical interlocking between the enclosure plate and the intermediate steel plate can be further ensured, and the lead elastic-plastic member can be uniformly deformed in the shear direction integrally with the laminated rubber portion at the time of shear deformation. it can.
Furthermore, the present invention is characterized in that some of the enclosure plates are fin enclosure plates formed integrally with fins that are parallel to the intermediate steel plate and shorter than the intermediate steel plate. In this case, the finned enclosure plate and the enclosure plate integrated with the intermediate steel plate are alternately laminated. Thereby, the pitch of rubber | gum of a rubber laminated body and an intermediate steel plate, and the pitch of the surrounding board in a restraint part can be selected suitably.
[0010]
Furthermore, the present invention is characterized in that spring elements are arranged in series on at least one of the upper and lower ends of the shroud laminate so as to give elastic characteristics in the vertical direction. As a result, it is possible not only to cope with horizontal deformation but also to cope with vertical distortion.
Further, the present invention is characterized in that the opening of the shroud is chamfered at the corner of the contact portion with the elastic-plastic material. The lead elastic-plastic member bites into the chamfered portion of the opening of the enclosure plate, thereby ensuring the interlock mechanism and preventing the portion that contacts the enclosure plate of the lead from being damaged during shear deformation.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
First, in FIG. 1 to FIG. 3, an experiment on the mechanical properties of the lead plug was performed, which will be described in relation to the principle of the present invention.
Lead used as an elastoplastic material is an unusual metal material close to so-called incompressible materials having n-crystal / grain growth at room temperature and a Poisson's ratio of 0.4 or more. Therefore, if the material is deformed in a state of being brought into close contact with an appropriate pressure and then returned to its original shape, a long life can be achieved without causing breakage by causing recrystallization and growth of crystal grains.
[0012]
Here, it demonstrates using "SED: Specific Energy Dissipation" as a parameter | index expressing energy absorption efficiency. This SED is obtained by normalizing the absorbed energy per round of force and displacement history curves using “volume: V” and “shear strain: γ”, and represents the energy absorption efficiency per unit volume.
In FIG. 1, both ends of a cylindrical lead 1 are supported and fixed by a collar 2, and in this state, the lead 3 is deformed after the central collar 3 is repeatedly shaken in the direction of arrow A (a) (b) ). In this case, SED = 18.1 to 22.1 for lead shear strain γ = 0.25 to 0.5. As described above, in the case of the bare lead plug, SED is about 20 in order to remain in the local deformation.
[0013]
FIG. 2 shows that a lead plug is sealed in a cylindrical lead 1 in which seven wide collars 4 are continuously arranged, both ends are fixed in the same manner as described above, and the central portion is repeatedly shaken in the direction of arrow A (a). The state (b) where the lead plug 1 is deformed later is shown. In this case, SED = 39.8 to 48.2 with respect to the shear strain γ = 0.25 to 0.5 of lead, and the maximum value of SED is about 50, and somewhat irregular deformation is observed.
[0014]
In FIG. 3, cylindrical lead 1 is sealed in a total of 16 thin washers 5 arranged in a row of 8 pieces in total, and both ends are fixed in the same manner as described above, and the central portion is repeatedly shaken in the direction of arrow A (a ) Shows a state (b) in which the lead 1 is deformed later. In this case, SED = 67.2-94.5 with respect to the lead shear strain γ = 0.25-0.5, which is a continuous and relatively regular deformation, and the maximum value of SED is 90 or more.
[0015]
Thus, as is clear from the experiments of FIGS. 1 to 3, when the sliding surface in the lead plug corresponding to the shear deformation is increased, a tendency for the SED to increase was observed. In this experiment, it was also found that the deformed lead plug does not return to its original shape due to plastic deformation, and the deformation concentrates only on the easily deformable portion.
Based on the above experimental results, the present invention avoids the concentration of deformation with respect to lead, which is an elastoplastic material, causes deformation with a uniform distribution, and further restores the original shape rather than lead. In order not only to enclose the lead plug with a metal with a large yield force stress, but also to make effective use of the elastic restoring force of laminated rubber in which rubber and intermediate steel sheets are laminated alternately, it is made of a metal with a greater yield force stress than lead. It is based on the principle that it is effective to enclose lead in a state where a large number of shrouds are laminated.
[0016]
Fig.4 (a) shows 1st Embodiment of the laminated rubber bearing with a lead plug of this invention. The laminated rubber bearing 10 with lead plugs is used to absorb the kinetic energy between two members that are spaced apart from each other in the vertical direction, such as the foundations and intermediate parts of civil engineering buildings such as bridges and buildings, and upper structures. Fixedly mounted between. That is, the lower flange 11 is fixed to the foundation (not shown) of the structure with, for example, a bolt, and the upper flange 12 is fixed to the upper structure (not shown) with a bolt or the like.
[0017]
Between the lower flange 11 and the upper flange 12, there is a laminated rubber portion 13. The laminated rubber portion 13 is formed by alternately laminating rubber 14 and intermediate steel plates 15 in the vertical direction. The intermediate steel plate 15 is composed of a metal having a yield stress greater than that of lead, typically a steel plate, and is formed as a laminated body integrated with rubber. The laminated rubber portion 13 is mainly responsible for elastic deformation due to shear strain in the horizontal direction.
[0018]
The laminated rubber portion 13 is provided with a hole 16 penetrating in the vertical direction, and the lead plug 1 whose periphery is surrounded by the restraining portion 17 is inserted into the hole 16. In this embodiment, the restraining portion 17 is made of a steel material integrally with the intermediate steel plate 15. That is, as shown in FIGS. 5A and 5B, a square thin plate-shaped peripheral portion is formed as an intermediate steel plate 15, and a thick circular portion at the center is formed as a surrounding plate 17 serving as a restraining portion. Has been.
[0019]
The surrounding plate 17 has an opening 18 that defines a through hole 16 into which the lead plug 1 is inserted at the center. When the surrounding plate 17 is stacked, the surrounding plate 17 is in close contact with an adjacent surrounding plate. A smooth surface sliding portion 19 for restraining the lead plug is provided. In this embodiment, as shown in FIG. 8, the sliding portion 19 is adjacent to the surface of the portion of the thick portion having a predetermined thickness t of the enclosure plate 17 in the radial direction W (FIG. 8). It is a contactable area | region with the surrounding board.
[0020]
R-shaped, round, or tapered chamfered portions 20 are formed on the upper and lower edges of the inner wall of the opening 18 of the enclosure plate 17. As will be described later, the chamfered portion 20 has the lead plug 1 biting into the chamfered portion 20 of the enclosure plate 17 so that the lead plug 1 and the enclosure plate 17 are subjected to shear deformation as shown in FIG. This is to prevent the surface of the lead plug from being damaged by contact at an angle of 90 degrees at the contact portion, that is, to receive concentrated local deformation.
[0021]
It is desirable that the upper and lower edge portions 21 on the outer side in the radial direction of the enclosure plate 17, that is, the connecting portion with the intermediate steel plate 15, be connected to the surface of the intermediate steel plate 15 in a smooth R shape, round shape or taper shape. Since the upper and lower connecting portions 21 are in contact with the rubber 14, when the shearing deformation as shown in FIG. 7 is applied, the portion of the rubber 14 adjacent to the connecting portion 21 is locally deformed greatly. This is to prevent it. Further, by applying a release agent or the like to the connecting portions 21 in advance and then integrating with the rubber, the connecting portion 21 and the rubber portion in the vicinity thereof are not mechanically bonded and non-bonded. It is desirable to be in an adhesive state.
[0022]
And the intermediate | middle steel plate 15 and the integral type enclosure board 17 are laminated | stacked. That is, the portion of the thick wall plate 17 is laminated so that the sliding portion 19 comes into contact with the sliding portion of the adjacent enclosure plate, while the portion of the thin intermediate steel plate 15 is between the adjacent intermediate steel plates. The interval at which the rubber 14 is laminated is defined.
In the integrated laminated rubber portion 13 and restraint portion 17 thus configured, lead 1 is inserted into the vertical through-hole 16 defined by the opening 18 of the surrounding plate 17. When there is no chamfered portion 20 in the surrounding plate 17, it is possible to press-fit cylindrical lead into the through-hole 16, but there is a chamfered portion 20 in the surrounding plate 17. In order to sufficiently spread the lead also in the circumferential groove, it is desirable to inject molten lead into the through-hole 16 and to cool and solidify. The lead plug 1 is a portion that plastically deforms when the laminated rubber bearing with the lead plug is subjected to shear deformation, and functions mainly as a damper by the plastic energy.
[0023]
FIG. 6 shows the shapes of the lower flange 11 and the upper flange 12. The lower flange 11 is in contact with the lowermost enclosure plate 17 and the upper flange 12 is in contact with the uppermost enclosure plate 17 and cooperates to seal the lead plug 1 in a hermetic manner. Therefore, the lower flange 11 and the upper flange 12 are designed so as to have a sliding portion 19a similar to the sliding portion 19 of the enclosure plate 17 in the portion that contacts the enclosure plate 17. That is, the portion corresponding to the sliding portion 19 of the enclosure plate 17 is raised by a dimension corresponding to the step between the enclosure plate 17 and the intermediate steel plate 15, and the flat contact is made by the same radial dimension of the sliding portion 19 of the enclosure plate 17. A part is formed and the upper and lower edges of the opening are chamfered.
[0024]
FIG. 4B shows a state in which a displacement in the shearing direction is generated between the lower flange 11 and the upper flange in the first embodiment. As described above, when the laminated rubber bearing with the lead plug is subjected to shear deformation, the laminated rubber portion 13 is elastically deformed and is in a regular inclined state as illustrated. This is because the laminated rubber portion 13 is formed by alternately laminating the rubber 14 and the intermediate steel plate 15 at substantially equal pitches in the vertical direction, and is relatively hard against vertical displacement, while allowing horizontal displacement. It is because it is comprised in the form which does.
[0025]
Therefore, the enclosure plates 17 that are integral with and laminated with the intermediate steel plate 15 are inclined together with the lead plug 1 that is an elastic-plastic member as shown in the figure, and the individual enclosure plates 17 are sequentially equal at their sliding portions 19. It will shift by the dimension. For this reason, the lead plug 1 held in a hermetically sealed state by the surrounding plate 17 causes a relatively uniform deformation in the vertical direction, and can prevent the upper and lower ends of the ball head from being seen in the bare lead plug.
[0026]
In FIG. 8, the sliding portion 19 of the shroud 17 has an overlap margin e with respect to the radial shift amount d even during a predetermined shear deformation. For example, even when the shear strain reaches 250%, the lead plug What is necessary is just to set the dimension of W so that 1 may be enclosed in the airtight state. Therefore, the sliding surface of the lead plug 1 can be reduced on the contact surface between the enclosure plate 17 and the lead plug 1, and when the laminated rubber portion 13 is restored to the original state by elastic deformation, the lead plug 1 has the original cylindrical shape. It can return to the state.
[0027]
In FIG. 8, conditions for obtaining an overlap margin e with respect to a radial shift amount d even during a predetermined shear deformation will be described. In FIG.
W: Radial dimension (sliding allowance) of the sliding part of the shroud
d: Sliding distance between two adjacent shrouds
e: Overlap allowance when two adjacent enclosures are displaced by the sliding distance d
t _S : Thickness of one sheet of intermediate steel
t _r : Rubber layer thickness between intermediate steel plates
t: Sum of thicknesses of one intermediate steel sheet and one rubber layer (t = t _S + T _r )
γ: Shear strain of lead (γ = d / t)
γ _max : Lead shear limit (eg, 250%)
Is defined as W = d + e, where γ = γ _max In this case, e> 0 must be satisfied.
[0028]
Also, the lead shear strain equation defined by γ = d / t, where γ _max Is set in the range of 30% or more and 300% or less, preferably 100 to 250%.
Furthermore, t = t _S + T _r The range of the sum of the thickness of one intermediate steel sheet and one rubber layer defined by the above is set to 2 mm or more and 100 mm or less, and preferably 2 mm to 30 mm.
FIG. 9A shows a second embodiment of the laminated rubber bearing with a lead plug of the present invention. The lower flange 11 and the upper flange 12 are the same as in the first embodiment. In the first embodiment, all the enclosure plates 17 are of the integral type with the intermediate steel plate 15. The second embodiment is the same as the first embodiment in that the laminated rubber portion 13 is formed by alternately laminating the rubber 14 and the intermediate steel plate 15 integrated with the enclosure plate 17 in the vertical direction. Every other intermediate steel sheet is degenerated and is formed as a fin 31 whose outer circumferential length is shortened. Further, the thickness of the portion of the surrounding plate 17 ′ is an example different from that of the surrounding plate 17 integrated with the intermediate steel plate 15.
[0029]
However, the opening into which the lead plug 1 provided in the central portion of the surrounding plate 17 ′ has the same inner diameter as the opening 18 of the intermediate steel plate 15 and the integral type surrounding plate 17, and the sliding portion 19 is exactly the same. is there. Furthermore, the shapes of the chamfered portions 20 on the upper and lower edges of the inner wall of the opening 18 and the connecting portions 21 with the fins 31 are exactly the same as those of the intermediate steel plate 15 and the integral enclosure plate 17.
[0030]
In this manner, the intermediate steel plate 15, the integral type enclosure plate 17, the fins 31 and the integral type enclosure plate 17 ′ are alternately laminated to form the restraint portion of the lead plug 1, so that As shown in FIG. 9 (b), the interval or pitch of the steel plates 15 is not so small, the pitch in the vertical direction of the enclosure plates 17 (17 ′) to be stacked is reduced, and the enclosure plates are arranged more densely. When the shear deformation is performed, the plastic deformation of the lead plug 1 can be made smoother. On the other hand, since the interval or pitch of the intermediate steel plates 15 in the laminated rubber portion 13 is not so small, the width in the vertical direction of the rubber layer 14 that causes elastic deformation is not greatly reduced. Deformation can be allowed.
[0031]
Although the size of the fins 31 is set to an appropriate size, since the fins 31 are integrally formed with the surrounding plate 17 ′, the elastic deformation in the shearing direction of the laminated rubber portion 13 is the same as that of the intermediate steel plate 15 and the integrated type surrounding plate 17. Can be smoothly transmitted to the lead plug 1. Other structures and operations are the same as those in the first embodiment.
Fig.10 (a) shows 3rd Embodiment of the laminated rubber bearing with a lead plug of this invention. In the first and second embodiments, the lead plug 1 is encapsulated by thickening the part of the intermediate steel plate or the fin-integrated enclosure, but in this third embodiment, the lead plug 1 is laminated more densely. In order to contain by a body, it was set as the form which does not provide a thick part. That is, it is a form in which the intermediate steel plate 32 having a uniform thickness is also arranged in a jumping manner, and the ring-shaped enclosure plate 33 is arranged therebetween. For example, as shown in the figure, two ring-shaped enclosure plates 33 having the same thickness as the intermediate steel sheet 32 are arranged between the intermediate steel sheets 32 also serving as enclosure plates.
[0032]
According to such a structure, when shear deformation occurs as shown in FIG. 10B, the ring-shaped shroud 33 that comes into contact with the intermediate rubber plate 13 in accordance with the horizontal movement of the intermediate steel plate 32 in the laminated rubber portion 13. In addition, following the movement of the intermediate steel plate 32, the same horizontal movement is caused, whereby the lead plug 1 can be smoothly plastically deformed.
If the number of the ring-shaped enclosures 33 disposed between the intermediate steel sheet 32 and the adjacent intermediate steel sheet 32 is excessively increased, the ring-shaped enclosure 33 separated from the intermediate steel sheet 32 sufficiently follows the intermediate steel sheet 32. Since there is a possibility that the operation cannot be performed, the followability of the ring-shaped surrounding plate 33 is good, and the thickness of the rubber layer 14 in the laminated rubber portion 13 is set to a level that allows a sufficient shear strain.
[0033]
For example, the thickness of the intermediate steel plate 32 and the ring-shaped surrounding plate 33 is in the range of 1 to 10 mm, preferably about 2 to 5 mm, the number of intermediate steel plates 32 is 2 to 50, and two adjacent intermediate plates It is appropriate that the number of ring-shaped surrounding plates 33 inserted between the steel plates 32 is 1 to 12.
When the thickness of the intermediate steel plate 32 and the ring-shaped surrounding plate 33 is equal (= t), when the relative displacement between adjacent plates is d, the shear strain (γ) of the lead plug is
γ = d / t
The design value is set so that the lower limit of this value is 30% or more and the upper limit is 300% or less.
[0034]
FIG. 11A shows a fourth embodiment similar to the third embodiment in a state where it has undergone shear strain. A difference from the third embodiment is that the upper and lower edges of the inner peripheral wall of the opening of the intermediate steel plate 32 serving also as the enclosure plate and the ring-shaped enclosure plate 33 are tapered. When the shear strain limit is set to 250%, the taper surface 35 of the intermediate steel plate 32 and the ring-shaped surrounding plate 33 is straight when the shear strain limit is 250%. It is desirable to set the angle so as to be in the vicinity or in the vicinity thereof. Further, when the shear strain limit is set to 300%, an angle at which the taper surface 35 of the intermediate steel plate 32 and the ring-shaped surrounding plate 33 are aligned in a straight line in a state of being deformed by applying a strain of 300% or its Needless to say, it should be set in the vicinity.
[0035]
Moreover, in 4th Embodiment shown to Fig.11 (a), even if it press-fits by inserting a cylindrical lead plug in the opening hole of the laminated body comprised by the intermediate | middle steel plate 32 and the ring-shaped enclosure board 33. FIG. Since the surface of the lead plug 1 does not adhere to the tapered surface 35, the lead plug 1 is brought into close contact with the tapered surface 35 by injecting molten lead and then solidifying by cooling after being melted. Accordingly, the lead plug 1 before being subjected to shear deformation is in a state as shown in FIG. 11B, and has a large number of tapered uneven surfaces 36 corresponding to the tapered surfaces 35 on the outer peripheral surface.
[0036]
FIG. 12 shows a fifth embodiment of a laminated rubber bearing with a lead plug according to the present invention. This embodiment is the same form as the first embodiment shown in FIG. 4A, but spring elements are arranged in series at the upper and lower ends of the restraining portion made of the surrounding plate 17 to give the elastic characteristics in the vertical direction. This is different from the first embodiment.
In the conventional bearing structure in which the vertical rigidity is maintained by the laminated rubber part in which rubber and intermediate steel plates are alternately laminated in the vertical direction, the vertical rigidity is 1000 to 2000 times the horizontal rigidity. It has rigidity. As in the first to fourth embodiments of the present invention described above, the vertical rigidity is maintained by the laminated portion of the shroud 17 in addition to the laminated rubber portion 13 in which the rubber 14 and the intermediate steel plate 15 are alternately laminated. In the structure, the rigidity in the vertical direction is further increased with respect to the rigidity in the horizontal direction.
[0037]
Even in such a case, there may be a situation where it is desired to reduce the rigidity in the vertical direction. For this reason, in the fifth embodiment, the portions of the upper and lower flanges 11 and 12 that are in contact with the surrounding plate 17 are configured as independent ring-shaped members 40, and the ring-shaped grooves 41 that are fitted to the ring-shaped members 40 are vertically After forming the flanges 11 and 12 and inserting the spring element 42 into the ring-shaped groove 41, the ring-shaped member 40 is inserted.
[0038]
Further, in a state where the ring-shaped member 40 is inserted into the ring-shaped groove 41, the sliding portion 40 a that comes into contact with the enclosure plate 17 protrudes from the opposing surface of the upper and lower flanges 11 and 12 and contacts the sliding portion 19 of the enclosure plate 17. To do. As the spring element 42, a rubber-like elastic body such as an elastomer is conceivable for supporting a large load.
FIG. 13 shows another embodiment in which a spring element is arranged in series with the restraint portion in the laminated rubber bearing with a lead plug of the present invention to give an elastic characteristic in the vertical direction. In this embodiment, the upper flange 12 has two parts, a peripheral part 12a corresponding to the laminated rubber part 13 for supporting load of an upper object such as a bridge or a building, and a central part 12b corresponding to the restraining part 17 for containing the lead plug 1. Divide into That is, the peripheral portion 12a is provided with a through hole 44 having a diameter corresponding to the diameter of the surrounding plate 17 forming the lead restraint portion, and after the central portion 12b is inserted into the through hole 44, a spring made of an elastomer or the like. Element 45 is inserted. The central portion 12 b has a ring-shaped sliding portion 46 that protrudes downward from the lower surface of the peripheral portion 12 a and contacts the sliding portion 19 of the surrounding plate 17, and this sliding portion 46 is the sliding portion 19 of the surrounding plate 17. It has a shape corresponding to.
[0039]
In this embodiment, the spring element 45 can be configured to be detachable from the laminated rubber bearing with a lead plug. Accordingly, in the construction site or the like, the elastic characteristics in the vertical direction can be adjusted by inserting or replacing other types of spring elements having different elastic moduli, for example, depending on the building.
14 shows a laminated rubber bearing with a lead plug according to the present invention (a bearing corresponding to the embodiment of FIG. 11) in which a spring element is arranged in series with a lead restraint portion to give an elastic characteristic in the vertical direction. The thing of another aspect is shown. In this embodiment, as described above, the upper flange 12 is divided into two parts, a peripheral part 12a corresponding to the laminated rubber part 13 and a central part 12b corresponding to the restraining part 17 for containing the lead plug 1. And the center part 12b is inserted in the through-hole 44 provided in the surrounding part 12a, and the disc spring 46 is inserted. The center part 12b contacts the uppermost enclosure board 17 which comprises the restraint part. Also in this embodiment, it goes without saying that the vertical rigidity can be adjusted by the disc spring 46 according to the building.
[0040]
In the embodiment of FIGS. 12 and 13, a laminated rubber bearing with a lead plug corresponding to the first embodiment will be described, and in the embodiment of FIG. 14, a laminated rubber bearing with a lead plug corresponding to the fourth embodiment. However, it should be noted that the configuration for obtaining elastic deformation in the vertical direction in these embodiments is applicable to each embodiment of the laminated rubber bearing with lead plug of the present invention.
[0041]
Although the embodiments of the present invention have been described in detail with reference to the accompanying drawings, the present invention is not limited to the above-described embodiments, and various forms, modifications, and modifications are within the spirit and scope of the present invention. It should be noted that etc. are possible.
For example, in the above-described embodiment, the intermediate plate 15 and the enclosure plate 17 are configured to be mechanically interlocked at the time of shear deformation by integrating the enclosure plate 17 constituting the restraining portion with the intermediate steel plate 15. Even if the enclosure plate 17 and the intermediate steel plate 15 are configured as separate bodies, and the enclosure plate 17 is merely arranged close to the periphery of the intermediate steel plate 15, the rigidity in the vertical direction is extremely high relative to the rigidity in the shearing direction, It can be mechanically linked.
[0042]
4 (a), (b), FIG. 7, FIG. 9 (a), (b), FIG. 12 and FIG. 13 show the rubber 14 and the intermediate steel plate 15 in order to clearly show the lead plug 1 portion. It should be noted that although the parts are shown short, they are actually long in the lateral direction.
[0043]
【The invention's effect】
As described above, according to the present invention, the lead plug has a property close to that of a non-compressible material having a Poisson's ratio of around 0.44. When undergoing deformation, the plastic energy of the lead plug is used. At that time, even when the shear strain reaches 250%, an overlap margin of the shroud is provided so that the lead plug can be contained. It is possible to cope with earthquake motion, and even when subjected to such a large shear strain, maintaining the lead plug in a sealed state prevents the lead from biting into the rubber layer and provides good damping efficiency. Moreover, a laminated rubber bearing with a long-life lead plug that prevents breakage of lead can be obtained.
[Brief description of the drawings]
FIG. 1 shows a state (a) in which an experiment of mechanical properties was conducted with a lead plug bare, and a deformation (b) of the lead plug after the experiment.
FIG. 2 shows a state (a) in which an experiment of mechanical properties was performed with a lead plug supported by a wide collar, and a deformation (b) of the lead plug after the experiment.
FIG. 3 shows a state (a) in which an experiment of mechanical properties was conducted with a lead plug supported by a number of ring-shaped washers, and a deformation (b) of the lead plug after the experiment.
FIG. 4 is a longitudinal sectional view (a) of a laminated rubber bearing with a lead plug according to a first embodiment of the present invention and a longitudinal sectional view (b) in a state of being subjected to shear strain.
FIG. 5 is a cross-sectional view (a) and a plan view (b) of an intermediate steel plate integrated with an intermediate steel plate used in the first embodiment of the present invention.
FIG. 6 is a sectional view (a) of the upper and lower flanges and a sectional view (b) of the enclosure plate.
FIG. 7 is a cross-sectional view showing a state in which the lead plug is subjected to shear strain in the first embodiment of the present invention.
FIG. 8 is a cross-sectional view (a) showing the dimensions of the enclosure plate in the first embodiment of the present invention, and a cross-sectional view (b) showing the dimensions of the enclosure plate in a state of being subjected to shear strain.
FIG. 9 is a longitudinal sectional view (a) of a laminated rubber bearing with a lead plug according to a second embodiment of the present invention, and a longitudinal sectional view (b) in a state of being subjected to shear strain.
FIG. 10 is a longitudinal sectional view (a) of a laminated rubber bearing with a lead plug according to a third embodiment of the present invention and a longitudinal sectional view (b) in a state of being subjected to shear strain.
FIG. 11 is a longitudinal sectional view (a) of a laminated rubber bearing with a lead plug according to a fourth embodiment of the present invention in a state of being subjected to shear strain, and a diagram (b) showing the shape of the lead plug before deformation.
FIG. 12 is a cross-sectional view showing a form allowing elastic deformation in the vertical direction in the laminated rubber bearing with lead plug of the present invention.
FIG. 13 is a cross-sectional view showing another embodiment that allows elastic deformation in the vertical direction in the laminated rubber bearing with lead plug of the present invention.
FIG. 14 is a cross-sectional view showing still another embodiment that allows elastic deformation in the vertical direction in the laminated rubber bearing with lead plug of the present invention.
[Explanation of symbols]
1 ... Lead plug (elastic-plastic material)
10 ... Laminated rubber bearing with lead plug
11 ... Lower flange
12 ... Upper flange
13 ... Laminated rubber part
14 ... Rubber
15 ... Intermediate steel plate
16 ... through hole
17 ... Restraint (enclosure)
18 ... Opening
19 ... sliding part
20 ... chamfer
21 ... Connection part
31 ... Fins
32 ... Intermediate steel plate
33 ... Ring-shaped shroud
35 ... Taper surface
40. Ring-shaped member
41 ... Ring groove
42 ... Spring element
44 ... through hole
45 ... Spring element
46 ... Belleville spring

Claims (5)

A laminated rubber portion formed by alternately laminating rubber and an intermediate steel plate in the vertical direction; an elastic-plastic material made of lead inserted into a hole provided through the laminated rubber portion in the vertical direction; In a laminated rubber bearing with a lead plug that absorbs kinetic energy between two members spaced apart in the vertical direction, comprising a restraining portion provided around the plastic material,
The constraining portion has a structure in which a plurality of enclosure plates made of a material having a yield stress equal to or higher than lead and having openings that define the holes are stacked in the vertical direction, and the enclosure plates are adjacent to adjacent enclosure plates. Further, a sliding portion having an overlap margin at the time of a predetermined shear deformation is provided, and at least some of the enclosure plates are between the intermediate steel plates so as to mechanically interlock with the intermediate steel plates at the time of shear deformation. A laminated rubber bearing with lead plugs, wherein the laminated rubber bearings are arranged in a positional relationship, and at least some of the surrounding plates are formed integrally with the intermediate steel plate .   At least some of the surrounding plates are finned surrounding plates that are formed integrally with fins that are parallel to the intermediate steel plate and that have a short distance from the intermediate steel plate to the outer circumferential direction. The laminated rubber bearing with a lead plug according to claim 1.   The laminated rubber bearing with lead plug according to claim 2, wherein the finned enclosure plate and the enclosure plate integrated with the intermediate steel plate are alternately laminated.   The laminated rubber bearing with a lead plug according to claim 1, wherein a spring element is arranged in series on at least one of the upper and lower ends of the enclosure laminated portion so as to give elastic characteristics in the vertical direction.   The laminated rubber bearing with lead plug according to claim 1, wherein the inner wall of the opening of the shroud is chamfered at the corner of the contact portion with the elastic-plastic material.

Images