JP3359465B2 - Laminated rubber bearing - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated rubber bearing,
In particular, the present invention relates to a laminated rubber bearing used as a seismic isolation isolator for seismic isolation and vibration isolation of buildings, civil engineering structures, equipment, and the like.

[0002]

2. Description of the Related Art As a seismic isolation isolator for protecting a structure such as a building from earthquake vibration, as shown in FIG. 4, a plurality of rubber plates 1 and metal plates (metal fittings) 2 such as steel plates are alternately arranged. There is a laminated rubber bearing body sandwiched between two metal plates (outer fittings) 3 from both upper and lower sides while vulcanizing and bonding, and a flange 4 is placed on each of the upper and lower sides of the outer fitting 3,
Used by connecting and fixing with bolts (not shown). When the laminated rubber is actually installed below the structure, a protective rubber layer (not shown) is covered or attached to a side peripheral portion of the rubber plate 1. Further, the outer fitting 3 and the flange 4 may be integrally formed.

As such a laminated rubber bearing, FIG.
(A), (b) and, as shown, respectively (c), the diameter or side length D ₃ of the middle bracket 2 is greater than the length D ₁ of the diameter or side rubber plate ₁ (D _3> D 1 ) Are formed and are conventionally used under surface pressure (compressive stress). Here, in the laminated rubber bearing shown in FIG. 5A, the entire side peripheral surface of the rubber plate 1 is a straight surface without any dent or inclination. In the laminated rubber bearing shown in FIG. 5 (b), the side peripheral surface of the rubber plate 1 has a curved surface portion having a small radius of curvature R on each of the upper and lower sides of a straight central portion having no dent or inclination. 5C, and in the laminated rubber bearing shown in FIG. 5C, the entire side peripheral surface of the rubber plate 1 is formed to be concave inward with a large radius of curvature R.

In particular, in the laminated rubber bearing shown in FIGS. 5B and 5C, a relatively low surface pressure σ (σ ≦ 20-40)
It has been confirmed that under Kgf / cm ² ), stress concentration on the bonding end of the rubber plate 1 is reduced.

[0005]

However, these laminated rubber bearings are usually used under a high surface pressure of 50 to 150 Kgf / cm ^{2 with} a surface pressure σ of 50 to 150 kgf / cm ² .
As shown in (a), (b) and (c), the side peripheral surface of the rubber plate 1 protrudes (bulges) outward and is bonded to the middle metal fitting 2 (indicated by A in the figure). ) Stress is concentrated. In addition, when vibration such as an earthquake occurs in a state of being supported at a high surface pressure, as shown in FIG. 7, the vibration is largely deformed in the horizontal direction, and the stress concentration on the bonding end of the rubber plate 1 is reduced. In the worst case, rubber breakage and product destruction occur.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and the stress concentration applied to the bonding end of a rubber plate with a metal plate at the time of high surface pressure and high shear strain (large deformation in the horizontal direction). It is an object of the present invention to provide a laminated rubber bearing having reduced pressure.

[0007]

The air spring device according to the present invention comprises a plurality of metal plates and a rubber plate having a diameter or a side length smaller than a diameter or a side length of the metal plates.
In a laminated rubber bearing body that is alternately laminated and bonded, the side peripheral surface of the rubber plate is rounded at the center in the thickness direction and has a radius of curvature R represented by the following equation, and is recessed inward. And, between the recess and the metal plate, have an inclined surface in contact with the recess,
The horizontal dimension from the side peripheral end of the metal plate of the concave portion of the rubber plate is L, and the horizontal dimension from the side peripheral end of the metal plate where the inclined surface is in contact with the metal plate is L _1. when the value of L ₁ / L is equal to or 0.4 to 0.5. R <0.5 t _R (where, t _R denotes a thickness of the one rubber plate.)

[0008]

In the laminated rubber bearing of the present invention, the center in the thickness direction of the peripheral surface of the rubber plate is formed to be inwardly concave with a radius of curvature R of less than 0.5 times the thickness t _R of the rubber plate. In addition, the intermediate portion between the concave portion and the metal plate laminated on both the upper and lower sides is an inclined surface in contact with the concave portion, so that even if high surface pressure and high shear strain are applied, the rubber plate is Less protrusion and less concentration of stress on the bonded end of the rubber plate.

As described above, in the laminated rubber bearing of the present invention,
Under high surface pressure and high shear strain, the stress concentration on the metal plate and the bonding end of the rubber plate is eased, so there is no damage such as rubber breakage or breakage, and high bearing capacity is exhibited .

[0010]

Embodiments of the present invention will be described below.

EXAMPLE As shown in FIG. 1, 5 26 circular rubber plates having a diameter of D ₁ 800 mm and a thickness of t _R 6 mm, and a circular steel plate (middle bracket) 6 having a diameter of D ₃ 820 mm and a thickness of 4.5 mm. Twenty-five sheets were alternately stacked, and two pieces of connected steel plates (outer fittings) having a diameter of 870 mm and a thickness of 22 mm were respectively stacked on the upper and lower rubber plates 5 and vulcanized to form a laminated rubber support.

As shown in the enlarged view of FIG. 2, the side peripheral surface 5a of each rubber plate 5 of the laminated rubber bearing has a central portion in the thickness direction at the thickness of the rubber plate 5 (t _R = 6 mm). rounded 0.3 times the curvature of the corresponding approximately 1.8mm in radius _{R (R = 0.3t R <0.5t} R) is attached, and the middle bracket 6 side peripheral edge portion than the maximum 10 mm (L
= 10 mm), and the surfaces connected to the upper and lower sides of the recess form a tangent to the recess in the cross section, and are closer to the side peripheral end of the metal fitting 6. At a position 4 mm inside (L ₁ = 4 mm), it has an inclined surface that is in contact with the middle fitting 6.

[0013] The laminated rubber bearing is about 500 to 800 tonf
Is used under a load of about 100 to 150 kgf / cm ² when converted to surface pressure σ, and the maximum surface pressure σ = 2
00Kgf / cm ² , horizontal displacement 30-40cm (shear strain 5
The movement is assumed to be 200-250% of the total thickness.

[0014] The laminated rubber bearing of such an embodiment includes:
When a surface pressure of 00 to 300 kgf / cm ² is applied, the side peripheral surface 5 a of each rubber plate 5 protrudes while taking the shape shown by the broken line in FIG. In this case, stress is not concentrated on A).

Therefore, a surface pressure (σ of 200 kgf / cm ² or less)
≦ 200 kgf / cm ² ), the curvature radius R of the concave portion of the rubber plate side peripheral surface 5 a is changed to the rubber plate 5 as in the embodiment.
0.3 times (R = 0.3t _R ), and L ₁ /
By setting the value of L to 0.4 to 0.5, sufficient bearing ability is exhibited. In addition, surface pressure of 200 kgf / cm ² or more (σ ≧ 200 kg
f / cm ² ), the radius of curvature R of the recess is 0.3 t _R or less (R ≦ 0.3 t _R ), and L ₁ /
It is desirable that the value of L be 0.5 or less.

In the above embodiment, a circular laminated rubber bearing body obtained by alternately laminating and bonding circular rubber plates and circular metal plates (middle metal fittings and outer metal fittings) has been described. However, the present invention is not limited to such a shape, and the same effect can be obtained in a square laminated rubber bearing in which a polygonal rubber plate such as a square and a metal plate of the same shape are laminated.

[0017]

As described above, the laminated rubber bearing of the present invention has excellent bearing capacity under high surface pressure,
Stress concentration on the bonded end of the rubber plate when high surface pressure and high shear strain are applied is reduced, so that damage such as rubber breakage or breakage does not occur. Therefore, high bearing capacity is exhibited for a long period of time, and it is suitable as a seismic isolation isolator.

[Brief description of the drawings]

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

FIG. 2 is an enlarged sectional view showing a main part of the laminated rubber bearing body of the embodiment.

FIG. 3 is a cross-sectional view showing a protruding shape of a rubber plate side peripheral surface when a surface pressure is applied to the laminated rubber bearing body of the embodiment.

FIG. 4 is a sectional view showing the structure of a conventional laminated rubber bearing.

FIG. 5 is an enlarged sectional view showing a main part of a conventional laminated rubber bearing.

FIG. 6 is a sectional view showing a protruding shape of a rubber plate when a high pressure is applied to a conventional laminated rubber bearing body.

FIG. 7 is a cross-sectional view showing a protruding shape of a rubber plate when a high bearing pressure and a high shear strain are applied to a conventional laminated rubber bearing body.

[Explanation of symbols]

 5 Rubber plate 5a Side peripheral surface 6 Middle bracket 7 Outer bracket

Claims (1)

(57) [Claims] 1. A laminated rubber bearing body comprising a plurality of metal plates and a rubber plate having a diameter or a side length smaller than a diameter or a side length of the metal plate alternately laminated and bonded, The side peripheral surface of the rubber plate is rounded at the center in the thickness direction, has a radius of curvature R represented by the following equation, and is concave inward, and between the concave portion and the metal plate, The metal plate has an inclined surface in contact with the concave portion, and further has a horizontal dimension L from a side peripheral end of the metal plate of the concave portion of the rubber plate, and the metal plate at a position where the inclined surface is in contact with the metal plate. Wherein the horizontal dimension from the side peripheral end is L ₁ , wherein the value of L ₁ / L is 0.4 to 0.5. R <0.5 t _R (where, t _R denotes a thickness of the one rubber plate.)