JPH07233565A - Laminated rubber support member - Google Patents

Abstract

PURPOSE:To enhance durability by laminating alternately a plurality of rigid plates and rubber boards having an open spiral-shaped or concentric circle- shaped groove on the surface without bonding each of them. CONSTITUTION:A rubber composition is molded in a vulcanizing fashion, thereby forming a disk-shaped rubber board 2 having an open spiral-shaped or concentric circle-shaped groove whose depth ranges from 0.1 to 0.5mm, and what is more, at a pitch within 10mm on the surface and whose surface roughness ranges from 20 to 80mum Ra. A middle rigid steel plate la and the rubber board 2 are alternately laminated without bonding each of them. A steel plate-made outer side rigid board is installed to the top and the bottom respectively.

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 used for seismic isolation of structures.

[0002]

2. Description of the Related Art Conventionally, as a base material for protecting a structure such as a building from an earthquake, a laminated rubber bearing having a plurality of rigid plates 1 and rubber plates 2 alternately laminated as shown in FIG. It is used. Particularly, in recent years, in such a laminated rubber bearing, the rigid plate 1 and the rubber plate 2 are simply stacked,
Alternatively, the so-called fixed type in which at least the peripheral portion is not attached does not have the hardening phenomenon as seen in the conventional adhesive type in which the rigid plate and the rubber plate are adhered to each other over the entire surface, and the tensile break of the rubber plate is prevented. For example, Japanese Patent Laid-Open No. 2-153137 has been receiving attention. The rigid plate 1 is composed of an intermediate rigid plate 1a arranged in the middle and an outer rigid plate 1b arranged outside. By the way, such a fixed type laminated rubber bearing uses a phenomenon in which an adhesive force is generated between the rigid plate and the vulcanized rubber when the rigid plate and the vulcanized rubber are brought into contact with each other under pressure, and a large vertical load is applied. Because of the addition, horizontal displacement does not occur in the contact surface between the rigid plate and the rubber plate due to some horizontal vibration. Therefore, it is considered that the characteristics are affected by the surface shape of the rubber plate used.

[0003]

However, the conventional fixed type laminated rubber bearing has various characteristics as described above, but on the other hand, it lacks stability at the time of compressive shear deformation, and as shown in FIG. There is a problem in that the shear plate strain causes non-uniform and large positional displacement between the rigid plate 1 and the rubber plate 2. That is, when such a phenomenon occurs, the laminated rubber bearing loses the bearing ability of the structure and does not function as a seismic isolation material.

Therefore, the present inventors have conducted extensive studies to find out the cause of the conventional fixed type laminated rubber bearing lacking in stability at the time of compressive shear deformation, and to find a countermeasure against it.
An open spiral or concentric groove with a groove depth of 0.1 to 0.5 mm and a groove pitch of 10 mm or less is provided on the surface of the rubber plate, or the surface roughness of the rubber plate is averaged. By adjusting the thickness to 20 to 80 μmRa, the surface shape of the rubber plate becomes the best, and as a result, the stability during compression shear deformation can be enhanced very effectively without impairing the releasability of the rubber plate from the mold. It has been found that a laminated rubber bearing having excellent durability can be obtained.

The present invention has been made on the basis of such findings, and has a rubber plate having an open spiral or concentric circular groove with a groove depth and groove pitch within a certain range, or a surface roughness within a certain range. By using a rubber plate having a thickness, it is possible to provide a laminated rubber bearing having excellent durability that does not cause a non-uniform and large positional displacement between the rigid plate and the rubber plate even when subjected to compressive shear deformation. To aim.

[0006]

A laminated rubber bearing of the present invention is a laminated rubber bearing in which a plurality of rigid plates and rubber plates are alternately laminated without adhering to each other and a heavy object is placed and supported thereon.
The rubber plate is characterized in that open spiral or concentric grooves having a groove depth of 0.1 to 0.5 mm and a groove pitch of 10 mm or less are provided on the surface of the rubber plate. Further, the laminated rubber bearing of the present invention is a laminated rubber bearing in which a plurality of rigid plates and rubber plates are alternately laminated without adhering, and a heavy object is placed and supported. , Average roughness 20-80
It is characterized by being μmRa.

In the present invention, a rubber composition containing carbon black in natural rubber or isoprene rubber is used as the rubber plate material.

Further, in the present invention, as a mold for vulcanizing and molding such a rubber composition, the groove depth is 0.1 to 0.5 mm and the groove pitch is 10 in advance in the mold.
Use those with open spiral or concentric groove processing within mm. This is because when the groove depth is less than 0.1 mm or when the groove pitch exceeds 10 mm, the effect of stabilizing the laminate during large deformation is impaired.
Further, if the groove depth exceeds 0.5 mm, the horizontal spring constant of the laminated body tends to vary, which is a drawback.

Incidentally, FIG. 2A is a plan view in which a groove 3 having an open spiral shape is provided on the surface of the rubber plate 2, and FIG. 2B is provided with a concentric circular groove 4 on the surface of the rubber plate 2. A top view is shown.

Further, in the present invention, as a mold for flow-molding such a rubber composition, a mold whose inner surface has a surface roughness of 20 to 80 μmRa by an appropriate method such as shot blasting is used. To do. This is because when the average roughness of the surface of the rubber plate is less than 20 μmRa, the effect of stabilizing the laminate in large deformation is impaired. If the average roughness exceeds 80 μmRa, the horizontal spring constant, which is important for laminated rubber performance, tends to vary.

[0011]

In the present invention, the surface of the rubber plate is provided with open spiral or concentric grooves having a groove depth and groove pitch within a certain range, or the surface of the rubber plate has a surface roughness within a certain range. The laminated rubber bearing obtained by alternately laminating a plurality of such rubber plates with a plurality of rigid plates has a stable behavior of the rigid plate and the rubber plate during compression shear deformation. It will be excellent in durability.

[0012]

EXAMPLES Next, examples of the present invention will be described.

Examples 1 to 5 Natural rubber (100 parts by weight) and carbon black (5 parts by weight) were mixed to obtain a rubber composition, while a predetermined groove depth and groove were formed on the inner surface of a steel mold for molding a rubber plate. Groove processing was performed at a pitch, and a lining layer made of fluororesin was further provided.
Next, the rubber composition is vulcanized and molded by this grooved mold to obtain a circular rubber plate 2 having a diameter of 500 mm and a thickness of 7 mm.
Was manufactured. Then, 10 circular rubber plates obtained,
Circular intermediate rigid plate made of metal with a diameter of 660 mm and a thickness of 6 mm 9
Sheets are alternately laminated in a non-wearing state, and a circular outer rigid plate made of metal with a diameter of 660 mm and a thickness of 18 mm is arranged on both sides of the sheet, and a fixed type laminated rubber is applied by applying an appropriate load in the thickness direction. A bearing was manufactured.

Comparative Examples 1 to 4 The same material and method as in Example 1 were used except that the groove processing on the inner surface of the mold was changed as shown in Table 1, and the diameter was 500 mm.
A circular rubber plate having a thickness of 7 mm was manufactured, and then 10 circular rubber plates thus obtained and 9 circular intermediate rigid plates made of metal having a diameter of 660 mm, a thickness of 6 mm and metal were alternately laminated. A metal circular outer rigid plate having a diameter of 660 mm and a thickness of 18 mm was arranged on both sides of the above, and a fixed type laminated rubber bearing was manufactured in the same manner as in Example 1.

Examples 6 to 8 A circle having a diameter of 500 mm and a thickness of 7 mm was prepared in the same manner as in Example 1 except that the inner surface of a steel mold for molding a rubber plate was made to have a predetermined surface roughness by shot blasting. A shaped rubber plate is manufactured, and then 10 obtained circular rubber plates and 9 circular intermediate rigid plates made of metal having a diameter of 660 mm and a thickness of 6 mm are alternately laminated in a non-mounted state, and 660mm diameter on both sides,
A metal-made circular outer rigid plate having a thickness of 18 mm was arranged, and a fixed laminated rubber bearing was manufactured in the same manner as in Example 1.

Comparative Examples 5 and 6 A circular rubber plate having a diameter of 500 mm and a thickness of 7 mm was manufactured in the same manner as in Example 6 except that the surface roughness of the inner surface of the mold was changed as shown in Table 2. Then, the obtained circular rubber plate 10
Sheets and 9 circular intermediate rigid plates made of metal with a diameter of 660 mm, thickness 6 mm are alternately laminated, and a circular outer rigid plate made of metal with a diameter of 660 mm, 18 mm and 18 mm is arranged on both sides of these. A fixed laminated rubber bearing was manufactured in the same manner as in Example 6.

A compression shear test was carried out on each of the laminated rubber bearings obtained in the above Examples and Comparative Examples, and the shear deformation rate (ratio of the shear deformation amount to the total rubber thickness) was 100%.
The maximum value Lmax (see FIG. 3) of the amount of displacement (positional deviation) of the intermediate rigid plate with respect to the outer rigid plate when changing to 200%, 300%, 400%, 500%, 600% was measured. The results are shown in Tables 1 and 2.

[0018]

[Table 1]

[Table 2] As is clear from Table 1 and Table 2, the laminated rubber bearing of the present invention is significantly superior in stability during compressive shear deformation as compared with that of the comparative example, and can be used as a seismic isolation isolator for a structure, or Can be used as anti-vibration rubber for machinery.

[0019]

As is apparent from the above embodiments, the laminated rubber bearing of the present invention has open spiral or concentric grooves with a groove depth and groove pitch within a certain range on the surface of the rubber plate. By providing or by setting the surface roughness of the rubber plate within a certain range, durability does not occur even if a compressive shear deformation is applied between the rigid plate and the rubber plate without causing uneven and large displacement. Is excellent.

Therefore, the laminated rubber bearing of the present invention is
It is useful as a seismic isolation isolator for structures or as a vibration isolator for machinery.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a state in which a laminated rubber bearing of the present invention is subjected to compressive shear deformation.

FIG. 2 (a) is a plan view showing an open spiral groove provided on the surface of a rubber plate of the laminated rubber bearing of the present invention, and FIG.
FIG. 6 is a plan view showing that a concentric groove is provided on the surface of the rubber plate of the laminated rubber bearing.

FIG. 3 is a cross-sectional view showing a state when a compressive shear deformation is applied to a conventional laminated rubber bearing.

[Explanation of symbols]

 1 ………… Steel plate 1a …… Intermediate rigid plate 1b …… Outer rigid plate 2 ………… Rubber plate

Claims (2)

[Claims] 1. A laminated rubber bearing body in which a plurality of rigid plates and rubber plates are alternately laminated without adhering and a heavy object is placed and supported, and a groove depth of 0.1 to 0 is formed on the surface of the rubber plate. A laminated rubber bearing characterized by having open spiral or concentric grooves with a groove pitch of 0.5 mm or less and 10 mm or less. 2. A laminated rubber bearing for alternately supporting a plurality of rigid plates and a rubber plate without adhering to each other and placing and supporting a heavy object, wherein the surface roughness of the surface of the rubber plate is an average roughness. 20-80
A laminated rubber bearing characterized by being μmRa.