JPH09269034A - Lead enclosing laminated rubber support - Google Patents

Abstract

PROBLEM TO BE SOLVED: To retain for a long time the predetermined pure shear deformation characteristics of a lead plug by forming a plastic deformation part in such a way that a metallic mesh cylinder formed of metallic wires is mounted around the periphery of the column lead plug, and closely enclosed in a circular hole in a laminated rubber body. SOLUTION: Pure lead and lead alloy are used for a lead plug 17, metallic wires formed into a cylindrical shape by being knitted, are used for a metallic mesh cylinder 18, and copper, copper alloy and stainless steel are used for a material. In view of the flexibility of the metallic mesh cylinder 18 and good following performance for the deformation of lead, the wire diameters and networks of the metallic wires are preferably set in a range of several number + μm several mm, and not to exceed 10mm, respectively. The metallic mesh cylinder 18 is formed in a condition that knitted wire mesh and woven wire mesh are slanted. When a plastic deformation part 4 is formed, the metallic mesh cylinder 18 formed in a predetermined size is previously inserted in a metal mold, and after that, fused lead is casted therein, then a column shape is closely enclosed in a circular hole 10. Hereby, a lead body 17 in the plastic deformation part 4 may not be bitten into a laminated rubber elastic layer 12, and can resist a long term use.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a so-called lead-sealing support device in which a lead body is enclosed in a laminated rubber body to support a load and to absorb vibration energy such as earthquake motion by utilizing shear deformation of the lead body. Regarding laminated rubber bearings.

[0002]

2. Description of the Related Art Lead-containing laminated rubber bearings of this type are generally
A structure in which a columnar lead body, a so-called lead plug, is enclosed in a laminated rubber body in which a rubber elastic layer and a reinforcing plate are alternately laminated in a vertical direction. Then, the lead plug is restrained by the laminated rubber body around the lead plug and is subjected to the pure shear deformation due to the horizontal displacement of the entire bearing, thereby exhibiting the desired energy absorption performance.

However, depending on the structure of the conventional lead-encapsulated laminated rubber bearing, intrusion of the lead plug into the rubber elastic layer or local deformation of the lead body occurs, and as a result, pure shear deformation cannot be received and the desired result cannot be obtained. The energy absorption characteristics of may not be obtained. This tendency is remarkable in a rubber elastic layer having a large thickness, for example, a laminated rubber bearing for a bridge.

[0004]

SUMMARY OF THE INVENTION In view of the above situation, the present invention has been made to overcome the drawbacks of the conventional lead-containing laminated rubber bearing having a thick rubber elastic layer. An object of the present invention is to obtain a lead-containing laminated rubber bearing in which a portion corresponding to a lead plug can maintain a predetermined pure shear deformation characteristic.

[0005]

The lead-containing laminated rubber bearing of the present invention has the following constitution in order to achieve the above object. That is, in a lead-sealed laminated rubber bearing in which a plastically deformable portion mainly composed of a lead body is enclosed in a columnar shape in a laminated rubber body in which a rubber elastic layer and a reinforcing plate are alternately laminated in a vertical direction, the plastically deformable portion is A metal mesh tube formed of a metal wire is attached to the outer circumference of a substantially cylindrical lead plug, and the lead mesh is closely sealed in a circular hole in the laminated rubber body.

(Operation) At all times, the laminated rubber body transfers and supports the load of the upper structure to the lower structure. The plastically deformed portion does not substantially participate in load bearing. Then, with respect to the slow expansion and contraction displacement of the upper structure due to the temperature difference, the plastically deformed portion follows the horizontal displacement and does not impair the horizontal elastic characteristics of the laminated rubber body. Moreover, the lead body in the plastically deformed portion resists the horizontal displacement against the wind load or the weak seismic force due to the initial elasticity. At the time of an earthquake, the upper and lower structures are suddenly displaced relative to each other in the horizontal direction against the forced vibration force, but the laminated rubber body follows this vibration displacement and, due to its horizontal spring characteristic, moves to the upper structure of this vibration cycle. It makes the transmission of the period longer and acts as a seismic isolation function for the superstructure. In addition, the plastic deformation of the lead body in the plastically deformed portion of the laminated rubber body absorbs seismic energy, damps the displacement acceleration of the superstructure, suppresses relative displacement, and performs a damping action.
In the deformation of the lead body in the plastically deformed portion, the lead body is constrained by the metal mesh cylinder, so the deformation of the lead body is pure shear deformation, and the desired energy absorption characteristics are exhibited. Further, even in the long term, the lead body is prevented from biting (bulging) into the rubber elastic layer.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a lead-filled laminated rubber bearing of the present invention will be described with reference to the drawings. (Structure of Embodiment) FIGS. 1 to 4 show a lead-sealed laminated rubber bearing S of one embodiment. That is, FIGS. 1 and 2 show the entire configuration, and FIGS. 3 and 4 show the configuration of that part. In the figure, G is an upper structure as a building structure, and B is a lower structure as a foundation for supporting the upper structure G.

Referring to FIGS. 1 and 2, a lead-sealed laminated rubber bearing S according to the present embodiment has a structure in which a laminated rubber body 1 is sandwiched and held between upper and lower thick flange steel plates 2 and 3, and A plastically deformable portion 4 having a body as a main body is enclosed, and is interposed between the upper structure G and the lower structure B.

The detailed structure of each part will be described below. Laminated Rubber Body 1 (Refer to FIGS. 1 and 2) The laminated rubber body 1 has a cylindrical outer shape, and a circular hole 10 penetrating in the vertical direction is formed in the center of the laminated rubber body 1. The annular portion of the laminated rubber body 1 has a structure in which the rubber elastic layers 12 and the reinforcing plates 13 are alternately arranged, and these are firmly integrated by vulcanization adhesion. Due to the rubber elastic layer 12 and the reinforcing plate 13, the laminated rubber body 1 exhibits a large rigidity with respect to the top load P and exhibits flexibility with the rubber elastic layer 12 against a lateral load Q. The cross-sectional area of the laminated rubber body 1 is determined so that the top load P can be supported.
The amount of each rubber in the rubber elastic layer 12 is preferably equal to obtain the same horizontal shear rigidity.

The reinforcing plate 13 has an annular shape and is formed of a thin steel plate in this embodiment, but a canvas, a synthetic resin plate or the like is not excluded. The outer diameter of the laminated rubber body 1 is made smaller than that of the laminated rubber body 1 with a required fogging, and the inner diameter of the laminated rubber body 1 is set to the inner hole
Equal to 0 diameter. In some cases, the inner diameter may have a fogging.

Upper and lower thick flange steel plates 2 and 3 (see FIGS. 1 and 2).
The upper and lower thick flange steel plates 2 and 3 are made of thick annular steel plates and are arranged above and below the laminated rubber body 1 and have circular holes 10 of the same diameter continuous to the circular holes 10 of the laminated rubber body. Is opened. In addition, on the upper and lower end surfaces, a screw hole 1 for attaching an anchor is provided.
5 (4 in this embodiment) are provided in the circumferential direction,
The upper structure G and the lower structure B are provided in the anchor screw holes 15.
An anchor steel rod (not shown) that is embedded and installed in is fixed by screwing. When welding the anchor steel rod, the screw hole 15 is omitted. This flange steel plate 2, 3
Is also integrated with the rubber elastic layer 13 of the laminated rubber body 1 by vulcanization adhesion.

Plastic Deformation Portion 4 (See FIGS. 3 and 4) The plastic deformation portion 4 has a characteristic structure in this embodiment. That is, the plastically deformable portion 4 is composed of a lead plug 17 and a metal mesh cylinder 18 fitted on the outer periphery of the lead plug 17, and has a cylindrical shape integrally and is closely sealed in the circular hole 10. To be done. (Lead plug 17) As a lead body used for the lead plug 17 of the plastically deformable portion 4, not only pure lead but also a lead alloy is applied. Pure lead has a specific gravity of 11.36 and a melting point of 327.4 ° C.
As mechanical properties, elastic modulus 13,631 MPa, elastic limit 1.66 MPa, tensile strength 14 MPa, elongation 40-50%,
A compressive strength of 49 MPa and a hardness of 3 to 7 HBS are shown. Thus, pure lead is highly malleable and is easily plastically deformed. As a lead alloy, Pb-Sb system, Pb-Sn system or Pb-
Sb-Sn alloy is applied. Of these, solder is S
It is contained in the b-Sn alloy, its characteristics are clear, and it is preferably used. (Metal mesh cylinder 18) The metal mesh cylinder 18 is shown in FIG.
As shown in (a), it is formed by braiding a metal wire into a cylindrical shape. Copper, copper alloy, and stainless steel are preferably used as the material of the metal wire, but other metal materials are not excluded. Regarding the wire diameter and the mesh size of the metal wire with respect to the metal mesh cylinder 18, it is preferable that the wire diameter is several tens of μm to several mm in view of the flexibility of the metal mesh cylinder 18 and the followability to the deformation of lead. Adopted,
In addition, the mesh does not exceed 10 mm, but is not particularly limited to this. The metal mesh cylinder 18 has a so-called braided wire mesh formed by weaving using metal wires of warp and weft as shown in FIG. A mode in which the direction of the metal line is oblique is also adopted.

(Attachment Mode of Metal Mesh Cylinder 18) The metal mesh cylinder 18 exhibits flexibility by virtue of the shifting action at the intersection points of the mesh, in contrast to the flexibility of the wire itself. Lead plug 17
Is exposed on the surface of the metal mesh cylinder 18 and in other words mixed with the mesh, and is also insulated and insulated from the laminated rubber 1 by the metal mesh cylinder 18. In the mode of the plastically deformable portion 4 shown in FIG. 3A, the metal mesh cylinder 18 is exposed on the surface of the lead plug 17, and the mode of the plastically deformable portion 4A shown in FIG. 3B is the metal mesh cylinder 18. The lead plug 17 is exposed on the surface of the lead plug 17, that is, the metal mesh cylinder 18 is embedded in the lead plug 17. Further, in the illustrated example, the metal mesh cylinder 18 is shown as a single cylindrical shape, but a metal mesh may be formed into a sheet shape and the sheet may be wound two to three times.

(Molding of plastically deformable portion 4) Metal mesh cylinder 1
The plastically deformed portion 4 including the lead plug 8 and the lead plug 17 is formed by the following method. A cylindrical metal mesh tube having a predetermined size is inserted into the inner circumference of the mold in advance, and then molten lead is cast. According to this aspect, the lead reaches the surface of the metal mesh cylinder, or alternatively, the metal mesh cylinder is embedded. Insert a cylindrical metal mesh cylinder having a predetermined dimension into the inner circumference of the mold, insert a lead plug having a diameter slightly smaller than the inner circumference of the metal mesh cylinder into the inner circumference of the metal mesh cylinder,
Pressure is applied from above and below in the mold to cause plastic deformation and lead to penetrate into the mesh of the metal mesh cylinder. According to this aspect,
By adjusting the pressure applied from above and below, it is possible to adjust the amount of lead that penetrates into the metal mesh cylinder.

The lead-sealed laminated rubber bearing S of this embodiment is installed between the upper structure G and the lower structure B. That is,
The lower structure B is, for example, a concrete foundation installed on the ground, the upper structure G is a medium-high-rise building having rigidity as a whole, and the lead-sealed laminated rubber bearing S supports the load of the upper structure G. Further, since the lead-containing laminated rubber bearing S has a circular cross section, it exhibits non-direction and can be installed in any direction.

(Operation / Effect of Embodiment) The operation of the lead-sealed laminated rubber bearing S of this embodiment will be described with reference to FIG. At all times, the laminated rubber body 1 transmits and supports the load P of the upper structure G to the lower structure B. The plastic deformation portion 4 does not substantially participate in load bearing. Then, with respect to the gradual expansion and contraction displacement of the upper structure due to the temperature difference, the plastic deformation portion 4 follows the horizontal displacement and does not impair the horizontal elastic characteristics of the laminated rubber body 1. In addition, wind load or weak seismic force q
On the other hand, the lead body 17 of the plastically deformable portion 4 resists by the initial elasticity and prevents the displacement in the horizontal direction.

At the time of an earthquake, the upper and lower structures G and B are suddenly displaced relative to each other in the horizontal direction with respect to the forced vibration force Q. The laminated rubber body 1 follows this vibration displacement and its horizontal spring characteristics. By this superstructure G of this vibration period
The transmission of the superstructure is made longer and seismic isolation of superstructure G is achieved.
Further, the plastic deformation of the lead body 17 of the plastic deformation portion 4 in the laminated rubber body 1 absorbs seismic energy, attenuates the displacement acceleration of the superstructure G, suppresses relative displacement, and performs a damping action. That is, in FIG. 5, the superstructure G is displaced in the direction a, and along with this, the lead-sealed laminated rubber bearing S also undergoes shear deformation as a whole, and in the plastic deformation portion 4, the lead body 17 is plastically deformed by shearing force. In response to this, the displacement in the direction a is braked. Subsequently, although the superstructure G is displaced in the direction opposite to the direction a, seismic energy is absorbed by the plastic deformation of the plastic deformation portion 4 and the displacement is damped. This displacement is periodic, and the vibration is promptly damped by the energy absorbing action of the plastic deformation portion 4.

In the deformation of the lead body 17 of the plastically deformable portion 4, since the lead body 17 is constrained by the metal mesh cylinder 18, the deformation of the lead body 17 becomes a pure shear deformation and exhibits desired energy absorption characteristics. To do.

According to the lead-encapsulated laminated rubber bearing S of this embodiment, the plastically deformable portion 4 undergoes pure shear deformation along with horizontal displacement of the entire bearing S, and exhibits the desired energy absorption characteristics according to the design specifications. Standardization is achieved. Further, the lead body 17 of the plastically deformable portion 4 does not bite into the rubber elastic layer 12 of the laminated rubber body 1 in the periphery, does not deform even after long-term use, and does not deteriorate in performance.

The present invention is not limited to the above embodiment, and various design changes can be made within the scope of the basic technical idea of the present invention. That is, the following embodiments are included in the technical scope of the present invention. In the above embodiments, the cylindrical lead-encapsulated laminated rubber bearing S is shown, but other shapes are not excluded. FIG. 6 and FIG. 7 show an example of a rectangular columnar lead-containing laminated rubber bearing S1 adopted for a bridge. In the figure, the same reference numerals are given to members equivalent to those in the previous embodiment. That is, this lead-filled laminated rubber bearing S
In No. 1, four plastic deformation portions 4 are arranged on the laminated rubber body 1 having a quadrangular cross section. In the plastically deformable portion 4, as shown in FIG. 8A, the metal mesh cylinder 18 is embedded in the upper and lower end surfaces of the lead plug 17 so as to be embedded. The illustrated example shows the upper end portion, and the same applies to the lower end portion. In the plastically deformable portion 4, as shown in FIG. 8B, a metal mesh 18 longer than the lead plug 14 is attached, and upper and lower extending portions are fixed with a cap 20. Further, the plastically deformable portion 4 is not limited to a circular shape, and may have a shape approximate to a circular shape such as an ellipse or a polygonal shape, and the hole 10 also has a shape corresponding thereto.

[0021]

According to the present invention, the plastically deformed portion is subjected to the pure shear deformation together with the horizontal displacement of the entire bearing, and exhibits the desired energy absorption characteristics according to the design specifications, and the standardization of the design is achieved. Further, the lead body in the plastically deformed portion does not excessively penetrate into the rubber elastic layer of the laminated rubber body around the lead body, does not cause an inconvenient deformation of the lead body even after long-term use, and does not deteriorate in performance. Furthermore, as a result, the rubber elastic layer of the laminated rubber body can be made as thick as possible, and the degree of freedom in design can be increased.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view (cross-sectional view taken along line I-I of FIG. 2) of a lead-filled laminated rubber bearing according to an embodiment of the present invention.

FIG. 2 is a cross-sectional plan view taken along the line II-II of FIG.

FIG. 3 is an enlarged cross-sectional view of a plastically deformed portion.

FIG. 4 is a main view of a metal mesh cylinder.

FIG. 5 is an explanatory view of the operation of this lead-filled laminated rubber bearing.

FIG. 6 is a vertical cross-sectional view of a lead-containing laminated rubber bearing according to another embodiment of the present invention (cross-sectional view taken along the line VI-VI in FIG. 7).

7 is a sectional view taken along line VII-VII of FIG.

FIG. 8 is a cross-sectional view of an upper portion of a metal mesh tube showing another aspect.

[Explanation of symbols]

S, S1 ... Lead-containing laminated rubber support, 1 ... laminated rubber body, 4 ...
Plastic deformation part, 10 ... Circular hole, 12 ... Rubber elastic layer, 13 ... Reinforcing plate, 17 ... Lead plug, 18 ... Metal mesh tube

Claims (3)

[Claims] 1. A lead-containing laminated rubber bearing in which a plastically deformable portion mainly composed of a lead body is enclosed in a columnar shape in a laminated rubber body in which a rubber elastic layer and a reinforcing plate are alternately laminated in a vertical direction, The deformable portion is characterized in that a metal mesh cylinder formed of a metal wire is attached to the outer periphery of a lead plug having a substantially cylindrical shape, and is closely sealed in a circular hole in the laminated rubber body. Lead-containing laminated rubber bearings. 2. A lead-containing laminated rubber bearing according to claim 1, wherein the metal mesh cylinder is embedded in a lead plug, and the lead plug is constrained by the laminated rubber body. 3. The lead-sealed laminated rubber bearing according to claim 1, wherein the lead plug is constrained in an insulating manner by the laminated rubber body by a metal mesh cylinder.