JPS6024727Y2 - Rubber bearing for high reaction force - Google Patents

Description

[Detailed description of the invention] This invention relates to a high reaction force rubber bearing for supporting long bridges.

Conventionally, rubber bearings for bridge bearings are shown in Figures 1 and 2.
As shown in the figure, a copper plate or other hard material layer 2 is integrally laminated on both upper and lower surfaces of a rubber layer 1 of uniform thickness by baking or the like.
A coating 3 made of rubber softer than the rubber layer 1 is integrally laminated on the surface of the hard material layer 2 by baking or the like.

And the allowable compressive stress of the rubber layer in the rubber bearing is 50~
Since the load is limited to about 55 kg/cJ, it is necessary to increase the area of the rubber bearing in proportion to the load of the bridge bearing.

On the other hand, when compressive force is applied to the rubber bearing, the periphery of the rubber layer 1 faces free space and bulges and deforms, so the periphery of the rubber bearing is compressed relatively easily, but the middle part of the rubber layer Since lateral deformation is restrained, a larger compressive stress acts on the middle part of the rubber layer than on the peripheral part.

For example, the plane dimension is 200rmn square, the thickness of the rubber layer 1 is 1
6771771, hard material layer 2 (steel plate) 2 thickness 1.6
When a compressive load is applied to a rubber bearing with a thickness of 7 rrm and a thickness of 3 TML made of a com coating 3, and the compressive stress distribution is examined, the results shown in FIG. 3 are obtained.

As can be seen from FIG. 3, the compressive stress increases rapidly from the peripheral edge S to the center C of the rubber bearing, and the difference in compressive stress increases as the area of the rubber bearing increases.

Further, as mentioned above, the allowable compressive stress of the rubber layer is suppressed to about 50 to 55 9/CiL, so in the case of a rubber bearing for a long bridge, the area needs to be considerably large.

However, if the area of the rubber bearing is made too large,
Not only is this uneconomical, but there is also the problem that the shear resistance of the rubber layer becomes excessive when the bridge expands and contracts.

The object of this invention is to provide a rubber bearing for high reaction force which advantageously solves the above-mentioned problems.

Next, this invention will be explained in detail using illustrated examples.

FIGS. 4 and 5 show an embodiment of this invention, in which a two-stage recess 5 with a deep central part is provided at the center of the rubber support on both sides of the rubber layer 1. The recess 5
is filled with a soft rubber layer 3 that is softer than the rubber layer 1,
A hard material layer 2 made of a steel plate and a rubber coating 4 are sequentially laminated on the upper and lower surfaces of the rubber layer 1 and the soft rubber layer 3, respectively. The coating 4 is integrally bonded by baking (pressure, heat).

The rubber layer 1 has a hardness of about 60 DEG, the soft rubber layer 3 has a hardness of about 50' to 55 DEG, and the rubber coating 4 has a hardness of about 400, for example.

This invention can also be implemented in a rubber bearing in which two rubber layers and three hard material layers are laminated alternately and integrally.

According to this invention, in a rubber bearing in which hard material layers 2 are laminated on both sides of a rubber layer 1 and are fixed to each other, there are two stages on the rubber bearing center side of the rubber layer 1, the central part of which is deeper. Since the recess 5 of the mold is provided and the recess 5 is filled with a soft rubber layer 3 that is softer than the rubber layer 1, the spring constant of the rubber bearing gradually decreases from the periphery toward the center. Therefore, the middle part of the rubber bearing can be compressed and deformed relatively easily and almost uniformly, so the maximum compressive stress in the middle part of the rubber bearing can be reduced, and the difference in compressive stress between the peripheral part and the middle part of the rubber bearing can be reduced. Therefore, the rubber bearing can be manufactured economically, and the structure is simple because it is only necessary to embed the block-shaped soft rubber layer 3 in the recess on the center side of the rubber bearing in the rubber layer 1. Effects such as ease of manufacture can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an example of a conventional rubber bearing, FIG. 2 is an enlarged cross-sectional view of a portion thereof, and FIG. 3 is a diagram showing a compressive stress distribution state of the conventional rubber bearing. FIG. 4 is a partially cutaway plan view showing a rubber bearing for high reaction force according to an embodiment of this invention, and FIG. 5 is an enlarged sectional view taken along the line B--B in FIG. 4. In the figure, 1 is a rubber layer, 2 is a hard material layer, 3 is a soft rubber layer, 4 is a comb coating, and 5 is a recess.

Claims (1)

[Scope of utility model registration request] In a rubber bearing in which hard material layers 2 are laminated on both sides of a rubber layer 1 and are integrally fixed, a two-stage recess 5 with a deep central part is provided at the center side of the rubber bearing in the rubber layer 1. A rubber bearing for high reaction force, characterized in that the concave portion 5 is filled with a soft rubber layer 3 that is softer than the rubber layer 1.