JP5522971B2 - Rubber washer, and support and structure using the rubber washer - Google Patents

Description

  The present invention relates to a rubber washer used for a laminated rubber body used in a seismic isolation structure in a building structure, and a bearing and a structure using the rubber washer.

  Structurally, bearing mounting structures for building structures and civil engineering structures, especially laminated rubber bodies used for seismic isolation structures in building structures, laminated rubber bodies used for seismic isolation structures and horizontal force distribution structures in civil engineering structures are structurally Although it has a high yield strength in the compression direction and can support the load of the superstructure, the yield strength in the tensile direction is inferior to that in the compression direction.

  Therefore, at the initial stage of development of a laminated rubber body as a seismic isolation device, a tensile force is not applied to the laminated rubber body, and damage and breakage of the laminated rubber body caused by the tensile force are prevented. The attachment to the structure was done by connecting with dowel pins, freeing the designer from studying the tensile force in the vertical direction.

  In this mounting structure, as shown in FIG. 10, the mounting plates 36 and 37 of the laminated rubber body 34 are fixed to the anchor plate 35 fixed to the lower structure 39 such as the foundation of the structure 31 and the upper structure 40. When the mounting bolt 32 and the cap nut 33 are fixed to the upper plate 38, and a large horizontal deformation acts on the laminated rubber body 34, the horizontal direction of the upper surface 34a and the lower surface 34b of the laminated rubber body 34 is relative to each other. Due to the deviation, a rotational moment is generated in the laminated rubber body 34, and a vertical pulling force is generated in the mounting structure portion of the laminated rubber body 34. However, when the laminated rubber body 34 and the dowel pins 35 protruding from the mounting plates 36 and 37 are separated, the pulling force can be released, and even in the case of a large horizontal deformation caused by a large earthquake, An excessive tensile force is not generated in the vertical direction of the rubber body 34. For this reason, damage and breakage of the laminated rubber body 34 can be preferably prevented, and further, excessive input is not applied to the attachment portion of the upper structure 40 to the laminated rubber body 34, so that the damage to the upper structure 40 is prevented. There is also an effect that can be prevented.

  However, in the above-mentioned dowel pin type joining method, the dowel pin part is separated at the time of horizontal deformation to a certain extent, and the tensile force in the vertical direction does not act on the support mounting structure part. There was a risk that the laminated rubber body itself would be deformed. In such a state, the horizontal resistance of the laminated rubber body is reduced, and there is a risk that the laminated rubber body will start to fall. Therefore, when adopting a mounting structure using dowel pins, the horizontal force is reduced. It was necessary to determine the use limit of the laminated rubber body with the amount as the fall limit (rollout displacement) (for example, see Non-Patent Document 1).

  Therefore, for the connection between the laminated rubber body and the upper and lower structures, a fastening means using a mounting bolt that does not need to consider the fall limit has been widely used. The designer of the laminated rubber body fully understands that the tensile strength of the laminated rubber body is low, and after confirming its characteristics by many experimental verifications, does not cause the laminated rubber body to generate a tensile force Even if it occurs, the design is performed in a state in which a high safety factor is secured in consideration of the tensile strength in the tensile direction.

  However, in recent years, the seismic isolation design of building structures has been applied to high-rise buildings and building structures with large aspect ratios, and accordingly, the development of laminated rubber bodies with high tensile capacity has been developed. It has been demanded. Moreover, in order not to transmit the tensile force more than the proof stress of a perpendicular direction to a laminated rubber body, the device which provides a floating prevention apparatus between an upper structure and the ground is made | formed.

  Furthermore, in addition to the device of the anti-lifting device arranged between the upper structure and the ground, for the purpose of not transmitting a large tensile force to the laminated rubber body, a method for binding the laminated rubber body to the upper and lower structures Various studies are underway.

  In this way, when the laminated rubber body is connected to the upper structure or the lower structure with the bolts, when the horizontal deformation exceeding the assumption occurs in the laminated rubber body, the laminated rubber body has a vertical moment due to the rotational moment. The tensile force in the direction acts, and there is a risk of damage to the laminated rubber body, damage to the structure due to excessive input to the superstructure or substructure, especially in buildings with a large aspect ratio There is a possibility that an excessive tensile force due to rocking at the time may act on the laminated rubber body.

  On the other hand, if a dowel pin type connection structure is adopted in order to avoid a tensile force in the vertical direction, there is a limit on the fall limit. For this reason, neither the connection structure using bolts nor the dowel pin connection structure is a satisfactory structure in selecting the connection method of the laminated rubber bodies.

  Therefore, for example, in Patent Document 1, one mounting plate fixed to one end surface of the laminated rubber seismic isolation device and one mounting plate outside the outer edge of one end surface of the laminated rubber seismic isolation device. And the other mounting fixed to the mounting surface of the foundation or structure facing the one end surface of the laminated rubber seismic isolation device inside the portion fixed to the one mounting plate. A mounting structure with a plate is described.

  According to this mounting structure, when a lift occurs between the upper structure and the lower structure, both the mounting plates are deformed, the mutual fixing portions of the both mounting plates move upward, and the mounting plate is bent. Since rigidity can be utilized, it is possible to avoid a large vertical tensile force from acting on the laminated rubber seismic isolation bearing device.

  Further, in Patent Document 2, in order to prevent the laminated rubber body from being damaged even if a pulling force is applied to the laminated rubber body, the flange members are bonded and fixed to the upper and lower sides of the laminated rubber body, and the protruding portion of the flange member is also disclosed. Describes a laminated rubber bearing body in which a thin-walled portion or an opening for reducing the bending rigidity of the flange member is formed.

  Furthermore, Patent Document 3 discloses that a laminated rubber body and a structure are fastened with bolts via a buffer seat (a disc spring made of steel) in order to ease the vertical load during a large earthquake and prevent the laminated rubber body from peeling off. The technology that binds is described. According to this, it is possible to cope with the displacement in the horizontal direction by the firm fastening with the bolt and to deal with the displacement in the vertical direction by the firm fastening through the buffer seat.

  In Patent Document 4, in a seismic isolation device in which flanges formed on the upper and lower sides of a laminated rubber are attached to upper and lower structures with bolts, a cylindrical rubber washer (buffer material) is provided between the head of the bolt and the flange. ) Is disclosed. According to this, even if a momentary lifting force is applied at the time of an earthquake, it is possible to escape the force due to deformation or destruction of the cushioning material, and to avoid the tensile force reaching the laminated rubber body.

Japanese Patent Laid-Open No. 2005-163281 JP 2002-195327 A JP-A-10-110551 JP-A-11-153191

By James M. Kerry, translated by Japan Vibration Technology Association / directed by Takashi Fujita, “Basic theory of seismic isolation structure and laminated rubber”, Tokyo Denki University Press, p160-p162

  However, a technique for reducing the tensile force applied to the laminated rubber body by making the mounting plate of the laminated rubber body a double structure as described in Patent Document 1 or by processing the flange as described in Patent Document 2. Then, the design change of the structure body of the laminated rubber body was accompanied by cost and time, and it was necessary to review the installation space, which was not easily applicable.

  On the other hand, the technique of interposing a cushioning material in the attachment portion of the laminated rubber body described in Patent Documents 3 and 4 is caused by large horizontal deformation of the laminated rubber body in addition to reducing the tensile force to the laminated rubber due to lifting. The pulling force can be reduced.

  However, as described in Patent Document 3, when a steel disc spring is used, rusting of the contact portion of the steel material and the elastically deformed portion becomes a problem. Further, as described in Patent Document 4, when a cylindrical rubber washer as a cushioning material is interposed between the head of the bolt and the flange, the inner peripheral surface of the cushioning material interferes with the bolt during compression, There is a risk of damage to the cushioning material.

  Therefore, the present invention has been made in view of the above problems, and does not involve a design change of the structure body of the laminated rubber body, does not require rust prevention, and does not cause damage to the cushioning material. The purpose is to provide washers.

To achieve the above object, the present invention provides a rubber washers are used in the mounting structure of the laminated rubber body, the seat gold, have a concave only in the inner circumferential surface of the cylindrical body made of a rubber material, the rubber A steel ring having an outer diameter larger than the outer diameter of the cylindrical body is bonded to both end faces of the cylindrical body of the washer . By using this rubber washer for the mounting structure of the laminated rubber body, the compression of the rubber washer against the tensile force applied to the end of the laminated rubber body by the rotational moment generated when the laminated rubber body is deformed relative to the horizontal direction. Because it can be countered by deformation of direction, etc., it can prevent excessive tensile force from acting on the laminated rubber body, and also does not cause excessive tensile force to act on the laminated rubber body and the fixing part of the structure The safety of the laminated rubber body and the seismic isolation structure can be improved.

  Further, according to the rubber washer according to the present invention, it is possible to suitably prevent the rubber washer from being damaged over a long period of time. Therefore, an excessive tensile force is generated in the laminated rubber body against the relative deformation in the horizontal direction of the laminated rubber body. As a result that can be stably avoided and can safely be expected to delay the hardening phenomenon in the restoring force characteristics that occurs in the case of a general mounting bolt fastening method, It is possible to extend a horizontal deformation region that causes a sudden increase in horizontal force caused by the hardening phenomenon of the laminated rubber body, and it is possible to increase the use limit horizontal deformation amount of the laminated rubber body of the same size.

  As described above, by using the rubber washer of the present invention, it becomes possible to stably increase the use limit horizontal deformation amount of the laminated rubber body of the same size stably, and therefore by the maximum horizontal force generated by the hardening phenomenon. In the case where the shape of the laminated rubber body is determined, the dimensions of the laminated rubber body can be kept smaller than before, which is preferable in terms of cost, resources, construction, and the like.

Further, the cylinder end surfaces of the rubber washer, by bonding a steel ring having an outer diameter greater than the outer diameter of the cylindrical body, compressive force to the cylindrical shape of the rubber material through a steel ring made Can act.

The rubber washer, by the concave, the wall thickness of the central portion in the longitudinal direction of the circular cylindrical body as possible out be configured to best thinner.

Further, the present invention is a laminated rubber bearings, rubber washer according to any one of the above, wherein the Rukoto provided without mounting structure to restrict the expansion of the outer diameter direction of the rubber washer. Thereby, as described above, an excessive tensile force does not act on the laminated rubber body, and an excessive tensile force does not act on the fixing portion of the laminated rubber body and the structure. Safety can be improved, and the size of the laminated rubber body can be kept smaller than before, which is preferable in terms of cost.

  Furthermore, this invention is a structure, Comprising: It is characterized by being supported by the said laminated rubber bearing. As described above, an excessive tensile force does not act on the laminated rubber body and the fixing portion of the structure, and the safety as the seismic isolation structure can be improved.

  As described above, according to the present invention, it is possible to provide a rubber washer or the like that does not require rust prevention and does not cause damage to the cushioning material without changing the design of the structural body of the laminated rubber body.

It is a figure which shows one Embodiment of the rubber washer concerning this invention, Comprising: (a) is a top view, (b) is the sectional view on the AA line of (a). It is a schematic diagram for demonstrating the deformation | transformation state of the conventional rubber washer. It is a schematic diagram for demonstrating the deformation | transformation state of the rubber washer concerning this invention. It is an observation figure of a state change at the time of changing a rubber washer concerning the present invention using a compression tester. It is a graph which shows the compression test result at the time of making the rubber washer concerning this invention deform | transform using a compression tester. It is the schematic which shows one Embodiment of the support and structure using the rubber washer concerning this invention. It is sectional drawing which shows the rubber washer shown in FIG. 6, and its vicinity. FIG. 7 is a schematic diagram illustrating a state in which a large horizontal relative deformation has occurred between the upper structure and the lower structure illustrated in FIG. 6. FIG. 7 is a schematic diagram illustrating a state where the upper structure illustrated in FIG. 6 is lifted in a vertical direction. It is the schematic which shows the state which the big horizontal relative deformation | transformation produced between the upper structure and lower structure provided with the conventional dowel pin.

  Next, an embodiment for carrying out the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows an embodiment of a rubber washer according to the present invention. The rubber washer 1 has a cylindrical rubber body 2 having a through hole 2a and an inner diameter substantially the same as the inner diameter of the rubber body 2. And ring-shaped flange plates 3 and 4 bonded to the upper and lower surfaces of the rubber body 2.

  The rubber body 2 plays a role as a cushioning material, and as shown in FIG. 1B, a concave portion 2c that is recessed toward the outer peripheral side surface is formed on the inner peripheral surface 2b. The recess 2c is continuously formed along the inner periphery of the rubber body 2, and is formed in an annular shape when viewed from above. At this time, it is preferable to form the recess 2c parallel to the flange plates 3 and 4 so that the position of the right recess 2c and the position of the left recess 2c are targeted in a cross-sectional view.

The concave portion 2c is formed so that the radial thickness of the rubber body 2 is the smallest at a position (center portion) 2d that is 1/2 of the length direction (height direction) of the rubber body 2. In addition, in FIG. 1, although the cross-sectional shape of the recessed part 2c is made into R shape, the shape of the recessed part 2c is not limited to this. For example, shapes other than the R shape such as a hyperbola shape and an ellipse shape can be adopted, and the concave inclination is constant, and the thickness of the rubber body 2 is the thinnest at the center in the length direction of the rubber body 2. It can also be formed into a V-shaped cross-sectional view.

  As the elastic material for forming the rubber body 2, natural rubber or synthetic rubber such as chloroprene rubber or urethane rubber can be used. At that time, a reinforcing material such as carbon can be added to adjust the hardness, elastic modulus, elongation, strength and the like as appropriate, and an anti-aging agent can be added as necessary to impart weather resistance.

  The flange plates 3 and 4 are formed of a steel material, specifically, a rolled steel material for general structure. When the flange plates 3 and 4 need to be subjected to corrosion resistance, it is preferable to apply paint or plating treatment to the range exposed to the atmosphere.

  The rubber body 2 and the flange plates 3 and 4 are preferably bonded by vulcanization adhesion at the time of rubber vulcanization. For molding, one of the flange plates 3 and 4 is vulcanized and bonded at the time of rubber vulcanization. The other can be bonded later, or both the flange plates 3 and 4 can be bonded after the rubber body 2 is vulcanized.

Next, a test example of the rubber washer 1 having the above configuration will be described with reference to FIGS. In carrying out the test, a circular cylinder-shaped rubber member 2 having a recess 2c (see FIG. 1), a straight cylindrical shape without a recess rubber body 6 (see FIG. 2 (a)) and the vertical direction in the target A compression force was applied to compare the deformation modes of the rubber bodies.

  First, as shown in FIG. 2, in the rubber body 6 having a constant thickness, when a vertical compressive force is applied, the rubber body 6 expands (see FIG. 2 (b)) or is directed outward or inward. Deformation (see FIGS. 2C and 2D), the deformation mode is not stable. In any of the deformation modes, since a part of the rubber body 6 enters the bolt arrangement region 7 (see FIG. 2A), the rubber body 6 comes into contact with the bolt (not shown), and the rubber There is a high risk of damaging the body 6.

  On the other hand, in the case of the rubber body 2 provided with the recess 2c, as shown in FIG. 3 (b), the central portion 2d of the rubber body 2 is thin and on the inner peripheral surface side of the rubber body 2. Since the concave portion 2c is provided, a force that pushes the central portion 2d in the outer peripheral direction acts when a vertical compressive force is applied. For this reason, the rubber body 2 always expands toward the outer peripheral direction, and a part of the rubber body 2 does not enter the bolt arrangement region 7 (see FIG. 3A). Therefore, the rubber body 2 does not come into contact with the bolt, and the rubber body 2 can be prevented from being damaged.

  Next, the state change of the rubber washer 1 when a compression load is applied to the rubber washer 1 using a compression tester, and the relationship between the load applied to the rubber washer 1 and the deformation amount of the rubber washer 1 are shown in FIGS. This will be described with reference to FIG. The size of the rubber washer 1 used in the test is as shown in FIG. 4A. Natural rubber is used for the rubber body 2, SUS304 is used for the flange plates 3 and 4, and an arrow is attached to the rubber washer 1. A compressive load was applied in the direction.

  The rubber washer 1 changes from the state of FIG. 4 (a) to the state of FIG. 4 (b) to FIG. 4 (e) as a compressive load is applied, and the deformation amount of the rubber washer 1 is shown in parentheses. Street. From these figures, it can be seen that the deformation state of the rubber washer 1 is deformed with uniform expansion in the outer peripheral direction.

Further, as shown in FIG. 5, as the compressive load is applied, the rubber washer 1 is substantially deformed with a resistance of 36 to 37 kgf at the time of 3 mm deformation at the initial stage of deformation, that is, a compression rigidity of 12.5 kgf / mm. It shows a stable linear deformation behavior up to an amount of 15 mm, and when it exceeds 15 mm, the resistance increases rapidly, and it can be understood that it can sufficiently withstand a load of up to 16 tons, that is, a surface pressure of 8273 kgf / cm ² . From these results, since the rubber washer according to the present invention can obtain a stable deformed shape without buckling during compression, the compression rigidity can also be obtained stably.

  Next, a support and a structure using the rubber washer 1 of FIG. 1 will be described with reference to FIGS.

  FIG. 6 shows a structure 11 in which the rubber washer 1 is used for the mounting structure of the laminated rubber body 14, and the rubber washer 1 has the mounting plates 16 and 17 of the laminated rubber body 14 and the lower structure such as the foundation of the structure 11. The anchor plate 15 fixed to the object 19 and the mounting bolt 12 for fixing to the upper plate 18 fixed to the upper structure 20 and the cap nut 13 are interposed.

  As shown in FIG. 7, the rubber washer 1 is placed on a mounting plate 16 of a laminated rubber body 14 (see FIG. 6), and mounting bolts 12 are inserted through the through holes 2a of the rubber body 2 of the rubber washer 1. The male threaded portion 12a of the mounting bolt 12 is screwed into the female threaded portion 13a of the cap nut 13 fixed to the anchor plate 15, and the mounting plate 16 of the laminated rubber body 14 is attached to the anchor plate 15 of the structure 11 (see FIG. 6). It is fixed. Similarly, the mounting plate 17 of the laminated rubber body 14 is fixed to the upper plate 18 of the structure 11. And, since the mounting bolt 12 can be tightened in a state where the rubber washer 1 is compressed so as to leave the amount of compression when lifting occurs, the mounting bolt 12 can be in a pre-tensioned state, Aged loosening of the mounting bolt 12 can also be prevented.

  When a large horizontal relative deformation occurs between the lower structure 19 and the upper structure 20 of the structure 11 using the rubber washer 1, as shown in FIG. A large tensile force acts by the rotational moment, and the mounting plates 16 and 17 warp in the direction of the arrow. At that time, the rubber washer 1 is compressed and deformed without interfering with the mounting bolt 12. In other words, if a tensile force acts in the axial direction of the mounting bolt 12, the rubber washer 1 does not buffer with the mounting bolt 12. Since the rubber body 2 is compressed and deformed, the tensile force applied to the laminated rubber body 14 can be absorbed by the compression deformation of the rubber body 2, and an excessive tensile force is prevented from acting on the laminated rubber body 14. be able to. In addition, an excessive tensile force is also applied between the fixing portion of the laminated rubber body 14 and the structure 11, that is, between the mounting plates 16 and 17 of the laminated rubber body 14 and the anchor plate 15 and the upper plate 18 of the structure 11. Therefore, the safety of the laminated rubber body 14 and the structure (seismic isolation structure) 11 is improved.

  Further, according to the rubber washer 1 according to the present invention, when a laminated rubber body is applied to a high-rise building or a building structure having a large aspect ratio in a seismic isolation design, and a part of the structure is lifted vertically by rocking or the like. In addition, as shown in FIG. 9, the laminated rubber can be compressed and deformed in the axial direction of the mounting bolt 12 that fastens the upper structure 20 and the laminated rubber body 14 without contacting the mounting bolt 12 on the inner peripheral surface. It is possible to prevent an excessive tensile force from acting on the body 14 and to prevent an excessive tensile force from acting between the laminated rubber body 14 and the mounting plate 17 which is a fixing portion of the structure 11 and the upper plate 18. It is possible to improve the safety of the laminated rubber body 14 and the structure (base-isolated structure) 11. And, since the compression rigidity of the rubber washer 1 is smaller than that of a washer using a steel material or the like, it is easy to separate the upper and lower mounting steel plates 16 and 17 of the laminated rubber body from the upper plate 18 or the anchor plate 15. The force acting on the laminated rubber body 14 and the attachment portion between the laminated rubber body 14 and the structure can be further reduced.

DESCRIPTION OF SYMBOLS 1 Rubber washer 2 Rubber body 2a Through-hole 2b Inner peripheral surface 2c Recessed part 2d Center part 3, 4 Flange plate 6 Rubber body 7 Bolt arrangement | positioning area | region 11 Structure 12 Mounting bolt 12a Male thread part 13 Cap nut 13a Female thread part 14 Laminated rubber body 15 Anchor plate 16, 17 Mounting plate 18 Upper plate 19 Lower structure 20 Upper structure

Claims (4)

A washer used for a laminated rubber body mounting structure,
The washer is
Have a concave only in the inner circumferential surface of the cylindrical body made of a rubber material,
A rubber washer, characterized in that a steel ring having an outer diameter larger than the outer diameter of the cylindrical body is bonded to both end faces of the cylindrical body of the rubber washer. It said concave surface, the rubber washer according to claim 1, characterized in that the wall thickness of the central portion in the length direction of the cylindrical body is configured so that the most thinner. A laminated rubber bearing, characterized in that the rubber washer according to claim 1 or 2 is provided in an attachment structure without restricting expansion of the rubber washer in the outer diameter direction. A structure which is supported by the laminated rubber bearing according to claim 3 .

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