JPH1129986A - Laminated rubber bearing body and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a laminated rubber bearing body to exhibit a high- performance damping characteristic by surely restraining slip between a damper member and a base isolating member. SOLUTION: A laminated rubber bearing body has, between supports secured to a structure, a base isolating member 5 in which deformable parts 10 made of rubber and deformation-resistant parts 11 made of a hard material are laminated alternately and which is provided with a cavity part 13 forming a hollow part closed by the spports, and has a damper member 6 disposed in the hollow part. The damper member 6 is closely filled into the hollow part, and the volume VL of the damper member 6 sealed inside the cavity part 13 is greater than 1.0 times but not greater than 1.05 times the volume VA of the cavity part 13 before the damper member 6 has been sealed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seismic isolation / seismic isolation bearing for reducing the acceleration of vibrations input to structures, various devices, arts and crafts, etc. due to, for example, earthquakes, mechanical vibrations, or traffic vibrations. The present invention relates to a laminated rubber bearing used and a method for producing the same.

[0002]

2. Description of the Related Art Acceleration of vibration applied to structures such as buildings, bridges, tanks, etc., and devices such as electronic computers, medical devices, security devices, precision manufacturing devices, analytical and analytical devices, and arts and crafts. For example, Japanese Patent Application Laid-Open No. 62-225666,
-46247, and Utility Model Registration No. 302144
There is known a laminated rubber bearing body as described in Japanese Patent Application Laid-Open No. 7-107.

As shown schematically in FIG. 11, for example, such a laminated rubber bearing body a includes a seismic isolation member b in which hard plates b1 such as steel plates and rubber plates b2 are alternately laminated, and a seismic isolation member b
And a damper member d such as a lead plug enclosed in a hollow portion c formed in the hollow portion c. The seismic isolation member b supports the weight of the structure and the like, and acts on the structure and the like from the foundation. Buffered. On the other hand, the damper member d
This has the effect of absorbing the vibration energy of the structure generated after the acting force is buffered by the seismic isolation member b, thereby attenuating the vibration of the structure itself.

[0004]

However, in the laminated rubber support a having such a structure in which the damper member d is enclosed,
The ratio d / c of the volume of the hollow portion c before the encapsulation and the volume of the damper member d to be encapsulated is the laminated rubber support a
Greatly affects the damping performance of the device. That is, when the damper member d having a volume less than the volume of the hollow portion c is sealed, the gap between the inner peripheral surface of the seismic isolation member b and the outer peripheral surface of the damper member, and the upper and lower end surfaces of the damper member d and the support plate e are not included. A gap is generated between them, and the shear deformation of the seismic isolation member b is not accurately transmitted to the damper member d, and the damping performance is significantly reduced.

[0005] However, even when the volume of the hollow portion c is equal to the volume of the damper member d and the gap does not occur, even when the seismic isolation member b is sheared and deformed, the distance between the seismic isolation member b and the damper member d is reduced. It was found that it was difficult to obtain the desired damping performance, for example, slippage occurred and transmission loss was caused.

Accordingly, the present inventor encloses a damper member d having a larger volume than the volume of the hollow portion c before encapsulation, and partially disposes the damper member d on the hard plate b1 on the inner peripheral surface of the seismic isolation member b. By letting you bite in between,
It has been found that slippage with the seismic isolation member b can be reliably suppressed and high-performance damping characteristics can be exhibited.

On the other hand, a part of the damper member d is replaced with a hard plate b1.
It is necessary to compress the damper member d and expand in the radial direction at the time of encapsulation in order to penetrate into the gap, but compression at a high compression pressure or at a high compression speed causes uneven expansion such as generation of local stress. In addition to reducing the damping performance,
There are also problems such as impairing strength and durability.

Accordingly, the present invention is to reduce the volume VL enclosed in the cavity of the damper member to 1.0 to 1.05 times the volume VA of the cavity of the seismic isolation member in an unloaded state before being enclosed. It is an object of the present invention to provide a laminated rubber bearing body capable of reliably suppressing slippage between a damper member and a seismic isolation member and exhibiting high-performance damping characteristics, and a method of manufacturing the same.

[0009]

In order to achieve the above object, a first invention of the present application is a laminated rubber bearing that is interposed between two structures and seismically isolated therebetween. Between the fixed supports, a deformed portion and a deformable portion are formed on a seismic isolation laminated base in which a sheet-shaped deformed portion made of a rubber material and a sheet-shaped deformable portion made of a hard material are alternately laminated. A seismic isolation member provided with a hollow portion that forms a hollow portion that is closed by the support tool, and a damper member for absorbing vibration energy disposed in the hollow portion,
The damper member is densely filled in the hollow portion, and the volume VL sealed in the hollow portion of the damper member is reduced by the volume of the hollow portion of the seismic isolation member in a no-load state before the damper member is sealed. It is characterized by being greater than 1.0 times VA and less than 1.05 times VA.

Before the damper member is sealed,
It is preferable that the hollow portion and the damper member have substantially similar cross sections and the diameter of the damper member is 0.9 times or more and smaller than 1.0 times the diameter of the hollow portion. The damper member can be enclosed without causing damage such as scratches on the surface,
It is preferable because a decrease in strength and durability can be suppressed.

At least one of the supports is formed of a substrate and a center cap that is loosely fitted to the substrate, and when filling the damper member, the center cap is pressed down to reduce the pressure and the subsequent stress relief. By gradually compressing while repeating the two or more cycles, it is possible to seal the damper member while uniformly expanding in the radial direction over the entire length thereof without causing deformation of the deformation-resistant portion of the seismic isolation member. This is preferable because it is possible to improve the damping performance by increasing the encapsulation accuracy, and to prevent the strength and durability from decreasing.

In addition, it is preferable that the damper member is formed as a continuous and integrated product at least in a portion disposed in the hollow portion, in order to further ensure the effect of improving the damping performance.

Further, the second invention of the present application is a seismic isolation device in which a sheet-shaped deformed portion made of a rubber material and a sheet-shaped deformable portion made of a hard material are alternately stacked between supports fixed to a structure. A seismic isolation member provided with a hollow portion that forms a hollow portion that passes through the deformed portion, the deformable portion, and is closed by the support member, and a vibration energy absorbing device that is disposed in the hollow portion. A method of manufacturing a laminated rubber bearing body including a damper member, wherein the filling of the damper member into the hollow portion is performed by reducing the volume VA of the hollow portion of the seismic isolation member in a no-load state.
It is characterized by using a damper member having a volume VL of 1.0 times or more and 1.05 times or less of the above, and press-fitting the damper member into the cavity by applying a load only to the damper member.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. In FIGS. 1 and 2, a laminated rubber bearing 1 is, for example, a seismic isolation between upper and lower supports 3A and 3B fixed to a lower structure 2B as a foundation and an upper structure 2A such as a building. A member 5 and a damper member 6 are provided.

At least one of the supports 3A and 3B is a plate-like substrate in which the upper and lower supports 3A and 3B are fixed to the respective structures 2A and 2B using fixing fittings such as bolts. 7 and a center cap 9 for loosely fitting the center hole 8 of the substrate 7 to close the center hole 8. The center hole 8 is provided with a small-diameter portion 8c via a step surface 8b inside a large-diameter portion 8a into which the center cap 9 is fitted.

The seismic isolation member 5 comprises a laminated base 12 for seismic isolation in which a sheet-like deformed portion 10 made of a rubber material and a sheet-shaped deformable portion 11 made of a hard material are alternately laminated. The laminated base 12 extends vertically through the deformable portion 10 and the deformation-resistant portion 11 so that the center hole 8 is formed.
Is formed. The cavity 13 is
The hollow portion 13 and the small diameter portion 8c form a series of hollow portions 14 in which the damper member 6 is filled.

The deformation-resistant portion 11 is made of a rigid metal plate such as a steel plate. In this embodiment, the deformation-resistant portion 11 is formed, for example, in a disk shape through the hole for forming the cavity. . Various rubber materials can be used as the deformed portion 10, but those having excellent mechanical strength, long-term stability of elastic modulus, long-term stability of deformability, and creep resistance are required.
For example, natural rubber (NR), chloroprene rubber (CR) and the like are preferably used. The thickness T1 of the deformable portion 10 is larger than the thickness T2 of the deformable portion, usually about 1.3 to 2.0,
In the present example, T1 = 4.2 mm and T2 = 2.5 mm are used.

The rubber vulcanization and / or adhesive of the deformed portion 10 after lamination is applied between the substrate 7 and the laminated base 12 and between the deformed portion 10 and the deformation resistant portion 11 of the laminated base 12. It is integrally and firmly connected by using. In this example, the outer periphery of the laminated base 12 is covered with the deformable portion 10 and the deformable portion 11, thereby protecting the seismic isolation member 5 from corrosion, damage, and the like. 15 are formed.

The damper member 6 is a straight columnar body made of a metal material that is easily plastically deformed, for example, lead.
4 is tightly filled (enclosed) with substantially no space.

At this time, the cavity 13 of the damper member 6 is
Is the volume V of the cavity 13 of the seismic isolation member 5 in a no-load state before the damper member 6 is sealed.
A is larger than 1.0 times and 1.05 times or less. More specifically, as shown in FIG. 3 (A), the inner peripheral surface of the cavity 13 in the no-load state before the encapsulation is substantially the inner surface of the deformable portion 10 and the inner surface of the deformable portion 11. In this example, the cross section is in the shape of a straight cylinder having a circular cross section, and the cross sectional shape matches the cross sectional shape of the small diameter portion 8c.

On the other hand, after the encapsulation, since VL> VA, the damper member 6 presses the inner peripheral surface of the hollow portion 13, and as shown in FIG. The amount of the damper member 6 corresponding to (VL-VA) bites into the soft deformable portion 10. The biting portion 6a of the damper member 6 has a wavy contour and is restrained by being sandwiched between the hard deformation-resistant portions 11, so that the slippage between the hollow portion 13 and the damper member 6 after sealing is performed. Is reliably suppressed, and the shearing deformation of the seismic isolation member 5 is accurately transmitted to the damper member 6 without causing a transmission loss, so that the damping performance can be greatly improved.

When the volume VL of the damper member 6 is equal to or less than 1.0 times the volume VA of the cavity 13 before sealing,
Since the bite does not occur, as schematically shown in FIG. 4, the transmission loss between the seismic isolation member 5 and the damper member 6 increases, and the damping performance is greatly reduced. On the other hand, when it exceeds 1.05 times, although the damping performance is maintained high, the amount of penetration of the damper member 6 becomes excessive and induces the adhesion peeling between the deformed portion 10 and the deformable portion 11, and This causes the deformation-resistant member 11 to bend and deform, such as torsion, thereby reducing strength and durability, and lowering the vibration damping effect of the seismic isolation member 5. Therefore, the upper limit of the volume VL is preferably 1.040 times or less, more preferably 1.035 times or less of the volume VA, and the lower limit is preferably 1.010 times or more, more preferably 1.020 times or more of the volume VA.

In order to make the damper member 6 bite between the deformable portions 11, it is necessary to compress the damper member 6 in the length direction and expand it in the radial direction at the time of sealing. That is, the sealing of the damper member 6 is performed as shown in FIG.
The laminated base 12 whose one end (for example, the lower end) of the through hole 8 is previously closed by fixing the center cap 9 is placed on the lower head M1 of the pressing machine M, and
The damper member 6 is inserted therein. The inserted non-compressed damper member 6 has a straight columnar shape whose cross-sectional shape is substantially similar to the cross-sectional shape of the hollow portion 13 before compression, and has a diameter D of the non-compressed damper member 6. Cavity 1 before compression
The diameter DR is 0.9 times or more and smaller than 1.0 times the diameter DR of No. 3. Thereby, it can be easily inserted without damaging the inner peripheral surface of the cavity 13. The cross-sectional shape of the damper member 6 and the like is not limited to a circle as in this example, but may be, for example,
It may be a non-circle including a polygon such as a pentagon, and at this time, the maximum width in the cross section is called a diameter. In addition, in order to facilitate insertion, the chamfered portion may be formed at one end or both ends of the damper member 6 before compression. However, since the chamfered portion remains even after sealing, when the chamfered portion is provided. Is preferably C5.0 mm or less.

If the diameter D is not less than 1.0 times the diameter DR, the damper member 6 may damage the deformed portion 10 on the inner peripheral surface of the cavity 13 at the time of insertion. As a result, the strength and durability are reduced, such as inducing delamination of the deformed portion 10 and the deformable portion 11. When the ratio is less than 0.9, the rate of expanding the damper member 6 in the radial direction by compression is unnecessarily increased, so that the workability in the compression stroke is significantly impaired, and uniform expansion is hardly obtained. Therefore,
The diameter D is preferably smaller than the diameter DR in the range of 0.5 to 1.0 mm.

On the inserted damper member 6, an upper center cap 9 is arranged, which presses down the center cap 9 as the upper head M2 of the press machine M descends and compresses the damper member 6. In other words, no compressive force is applied to the seismic isolation member 5 placed on the lower head M1, and the damper member 6
A compressive force is applied only to this, and press-fits into the hollow portion 14.

According to this press-fitting method, since the volume of the hollow portion 14 is always kept constant without changing, and only the damper member 6 is compressed and deformed, uniform filling can be performed and the performance of the support body can be stabilized. sell. Further, according to this press-fitting method, the load can be applied only to the center cap 9, so that the apparatus can be downsized and energy can be saved.
It can greatly contribute to cost reduction. In the conventional method,
Since the laminated rubber support itself was loaded and the damper member was sealed, a large-scale dedicated load-loading device was required.

In the press-fitting, it is necessary to convert the compression strain (longitudinal strain) of the damper member 6 into the radial expansion (lateral strain) substantially uniformly over the entire length. In this method, two or more cycles of pressurization and subsequent stress relaxation are repeated until the final filling pressure is reached, and the material is gradually compressed. More specifically, the compression between the center cap 9 and the fixed position where the center cap 9 is fitted into the substrate 7 and abuts on the step 8b is performed in, for example, a plurality of steps.
As schematically shown in (A), after a first pressurizing step 16A in which a predetermined length of compression is performed by an initial (first) forced pressurization, a first stress relaxation step in which this compression height is maintained 1
Perform 7A and wait until the internal stress is relaxed and the longitudinal strain is converted to a transverse strain.

The cycle consisting of the pressing step 16 and the stress relaxing step 17 is performed two or more times, for example, three cycles, and after the center cap 9 is arranged at the fixed position by the final (third) pressing step 16C. Final (third)
The stress relaxation step 17C confirms whether the stress relaxation has reached an equilibrium state. This check confirms that the pressure drop is 1
Performed by being 0 per minute. In each pressing step 16, it is preferable that the compression speed is sufficiently low (for example, 1500 kgf / cm ² · sec or less) in consideration of the stress relaxation speed, and the final filling pressure is 160
Preferably, the pressure is 0 kgf / cm ² or less. If the compression speed exceeds 2000 kgf / cm ² · sec, the hollow part 1
A caulked portion of the damper member 6 is likely to be formed near the upper end of 4, and there is a possibility that the compression may be uneven. When the final filling pressure is more than 2000 kgf / cm ² , the laminated base 12 bends in the deformation-resistant portion, causing deformation such as twisting.

The fixed position of the center cap 9 and the substrate 7
Is fixed by welding, and the upper end of the hollow portion 14 is closed to enclose the damper member 6. As shown in FIG. 8, the center cap 9 is provided with a chamfer 19 at an outer end thereof at a height of 10 to 30% of the height of the center cap 9. The welding material 21 enters the groove 20 between
The center cap 9 is securely fixed to prevent the center cap 9 from being pushed up by the sealing pressure.

In order for the damper member 6 to exhibit the specified damping performance, the damper member 6 must be a continuous and integral part at least at the portion disposed in the cavity 13 in the sealed state. is necessary. In other words, in the portion arranged in the small diameter portion 8c, the damper member 6 may be divided into thin plate-shaped member pieces, and by adding this member piece, adjustment of the volume, which is the sealing amount of the damper member 6, can be achieved. It becomes possible.

Here, assuming that the volume of the cavity 13 before filling is VA, the diameter of the cavity 13 is DR, and the height of the cavity 13 is HL, VA = π · DR ² · HL / 4. It is represented by (1). That is, VA is determined by the dimensions when the laminated rubber base 12 is formed. In addition, cavity 1 after encapsulation
The volume VL of the damper member 6 enclosed in 3 is represented by VL = (1.0 to 1.05) · VA, where Do is the effective diameter of the damper member 6 when enclosed. . That is, the bite amount VL of the damper member 6
By setting -VA in the range of (0-0.05) .VA, the effective diameter Do is determined. The cavity 1
Assuming that the diameter of the damper member 6 sealed in 3 before the sealing is D, the length is h ′, and the Poisson's ratio (longitudinal strain / lateral strain) of the damper member 6 is ν, ν = ｛(Do−D) / Do｝ / {(h′−HL) / HL}... When the material of the damper member 6 is set, for example, in the case of lead, the Poisson's ratio ν is 0.44, and the diameter D is selected in the range of 0.9 to 1.0 times the DR. According to the above formulas (1) to
According to (3), dimensions such as the height h ′ can be set. In addition,
The total volume of the damper member 6 which is a material needs to be the volume V V = π · DR ² · (h1 + h2) / 4 filled in the small diameter portion 8c in addition to the volume VL. Therefore, substantially, the total length h of the damper member 6 as a material is h ′ + DR ² · (h1 + h2) /
D2. Here, h1 and h2 are the lengths of the small diameter portion 8c, respectively.

The inner peripheral surface of the hollow portion 14 is
As shown in (A), an inner rubber layer 22 for buffering minute vibrations may be formed. At this time, similarly, the damper member 6
As shown in FIG. 9 (B), after enclosing, the biting portion 6a which bites in the radial direction between the deformation resistant portions 11 is formed in a wavy shape.

[0033]

EXAMPLES A laminated rubber bearing having the structure shown in FIGS. 1 and 2 was prototyped based on the specifications shown in Table 1, and each prototype was dismantled to confirm whether or not a biting portion was formed in the damper member. The dimensions of the laminated rubber supports of Examples 1 to 4 and Comparative Examples 1 to 3 are φ240 mm (outer diameter) × 110 mm.
(Height), and the dimensions of the laminated rubber supports of Examples 5 to 9 were φ600 mm (outer diameter) × 250 mm (height).

[0034]

[Table 1]

As shown in Table 1, in the laminated rubber bearings of Examples 1 to 9, it can be seen that the wavy digging portion is formed on the peripheral surface of the damper member, and the transmission loss with the seismic isolation member is suppressed. .

FIG. 10 shows the relationship between the lateral force (horizontal force) δ and the lateral displacement (horizontal displacement) δ when a lateral force (horizontal force) F is generated in the laminated rubber bearing member of the first embodiment. In addition to the solid line, the relationship between the lateral force F and the lateral displacement (horizontal displacement) δ in Comparative Example 3 in which the ratio VL / VA is 1.0 is indicated by a broken line. It is to be noted that the larger the area in the curve, the higher the effect of absorbing vibration energy, and it can be seen that Example 1 is superior to Comparative Example 3 in damping performance.

FIGS. 6 (A) to 6 (F) show the pressurizing steps during the production of Examples 1-4 and Comparative Examples 1-3. FIG.
As shown in (A) to (F), it can be seen that as the ratio VL / VA increases, the stress relaxation time becomes longer, and a longer time is required for the compression stroke. As shown in FIG. 7, the relative pressure drop due to stress relaxation is such that as the ratio VL / VA increases, the pressure drop with respect to the input forced pressure value increases.

[0038]

As described above, in the laminated rubber bearing of the first invention, the volume VL sealed in the cavity of the damper member is 1.0 to 1.05 times the volume VA of the cavity before sealing. Because of the following, slip between the damper member and the seismic isolation member can be reliably suppressed, and high-performance damping characteristics can be exhibited.

In the method of manufacturing a laminated rubber bearing according to the second aspect of the present invention, when the damper member is filled, the hollow member is formed by applying a compressive force only to the damper member while maintaining a non-load state where no compressive force is applied to the seismic isolation member. Since the device is press-fitted into the unit, the size of the device can be reduced, energy can be saved, and cost can be greatly reduced. Therefore, even when the volume VL of the damper member is set to 1.0 times the volume VA of the hollow portion, the above-described effects such as miniaturization of the device can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a laminated rubber bearing according to one embodiment of the present invention.

FIG. 2 is a plan view thereof.

FIG. 3A is a cross-sectional view showing a relationship between a seismic isolation member and a damper member before sealing, and FIG. 3B is a cross-sectional view showing a relationship between the seismic isolation member and a damper member after sealing.

FIG. 4 is a schematic diagram showing the relationship between the ratio VL / VA and vibration energy-absorption.

FIG. 5 is a cross-sectional view illustrating a step of enclosing a damper member.

FIGS. 6 (A) to 6 (F) are diagrams illustrating a pressurizing step at the time of preparing Examples 1 to 4 and Comparative Examples 1 and 2, respectively.

FIG. 7 shows a relative pressure drop due to stress relaxation and a ratio VL /
FIG. 4 is a diagram showing a relationship with VA.

FIG. 8 is a sectional view illustrating a center cap.

FIG. 9A is a cross-sectional view showing the relationship between the seismic isolation member and the damper member before enclosing in another embodiment of the seismic isolation member, FIG.
FIG. 3 is a cross-sectional view showing the relationship after sealing.

FIG. 10 is a diagram showing a relationship between a lateral force F acting on a laminated rubber bearing body and a lateral displacement (horizontal displacement) δ.

FIG. 11 is a cross-sectional view illustrating a conventional laminated rubber bearing.

[Explanation of symbols]

 2A, 2B Structure 3A, 3B Support 5 Seismic isolation member 6 Damper member 7 Substrate 9 Center cap 10 Deformation part 11 Deformation resistant part 12 Laminated base 13 Cavity part 14 Hollow part

Claims (5)

[Claims] 1. A laminated rubber bearing interposed between two structures and seismically isolated between the two structures, wherein a sheet-shaped deformed portion made of a rubber material and a rigid member are interposed between supports fixed to the structures. A laminated body for seismic isolation, in which sheet-shaped deformation-resistant portions made of a material are alternately stacked, is provided with a cavity portion that passes through the deformation portion and the deformation-resistant portion and forms a hollow portion closed by the support. A seismic isolation member, and a damper member for absorbing vibration energy disposed in the hollow portion, wherein the damper member is densely filled in the hollow portion, and furthermore, has a volume VL sealed in the hollow portion of the damper member. Wherein the volume VA of the hollow portion of the seismic isolation member in a no-load state before the damper member is sealed is greater than 1.0 times and 1.05 times or less. 2. The method according to claim 1, wherein the cavity and the damper member are substantially similar in cross section before the damper member is sealed, and the diameter of the damper member is at least 0.9 times the diameter of the cavity and at least 1.0. 2. The laminated rubber bearing according to claim 1, wherein the thickness is smaller than twice. 3. The supporting tool comprises at least one of a substrate and a center cap which is loosely fitted to the substrate and closes the hollow portion, and the damper member is provided at the hollow portion with a final filling pressure. 3. The laminated rubber bearing body according to claim 1, wherein two or more cycles of pressurization and subsequent stress relaxation are repeated by pressing down the center cap, and gradually compressed and filled. 4. The laminated rubber bearing according to claim 1, wherein the damper member is a continuous and integral product at least at a portion disposed in the hollow portion. 5. A laminated base for seismic isolation in which a sheet-like deformed portion made of a rubber material and a sheet-shaped deformable portion made of a hard material are alternately laminated between supports fixed to a structure. A lamination comprising a seismic isolation member provided with a cavity forming a hollow portion passing through the deformable portion, the deformation-resistant portion and closed by the support, and a damper member arranged in the hollow portion for absorbing vibration energy A method of manufacturing a rubber bearing body, wherein the filling of the damper member into the cavity is performed in a volume VL of 1.0 to 1.05 times the volume VA of the cavity of the seismic isolation member in a no-load state. A method of manufacturing a laminated rubber bearing, characterized in that a damper member having the following is used, and a load is applied only to the damper member to press-fit the damper member into the hollow portion.