JPS6011133Y2 - 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 steel 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 rubber coating 4, which is 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/ctf'r, 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 peripheral surface of the rubber layer 1 faces the free space and bulges and deforms, so the peripheral part of the rubber bearing is compressed relatively easily, but the middle part of the rubber layer Since the deformation of the rubber layer in the lateral direction is restrained, a larger compressive stress acts on the middle portion of the rubber layer than on the peripheral portion.

For example, the plane dimension is 20orrrIIt square, the thickness of the rubber layer 1 is 16mm, and the thickness of the hard material layer (steel plate) 2 is 1.6rr.
r! Thickness of n1 rubber coating 4 is 3rfr! When a compressive load is applied to the rubber bearing of the IL and the compressive stress distribution is investigated, 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/cft, 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.

4 and 5 show a first embodiment of this invention, in which a rectangular rubber bearing in which hard material layers 2 are laminated and integrally fixed on both sides of a rubber layer 1, a steel plate is used. A soft rubber layer 3 is interposed between the hard material layers 2 which are made of a rubber material that is the same thickness as the rubber layer 1 and is softer than the rubber layer 1 and extends between the central portions of the opposite long sides of the rubber bearing. and a rubber coating 4 on the outer surface of the hard material layer 2.
The rubber layer 1, the soft rubber layer 3, the hard material layer 2, and the rubber coating 4 are bonded together by baking (pressure, heat).

FIGS. 6 and 7 show a second embodiment of this invention, in which a plurality of soft rubber layers 3 are provided in parallel, extending between the intermediate portions of the opposing long sides of the rubber bearing, A rubber layer 1 is also interposed between adjacent soft rubber layers 3, but the other configurations are the same as in the first embodiment.

The rubber layer 1 has a hardness of about 60 DEG, the soft rubber layer 3 has a hardness of about 50 DEG to 55 DEG, and the rubber coating 4 has a hardness of about 40 DEG, 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 rectangular rubber bearing in which hard material layers 2 are laminated on both sides of a rubber layer 1 and are fixed together, there is a space between the hard material layers 2 that is equal in thickness to the rubber layer 1 and A soft rubber layer 3 made of a rubber material with a higher quality than the rubber layer 1 and extending between the intermediate portions of the opposing long sides of the rubber bearing.
is interposed therebetween, and the soft rubber layer 3 is integrally fixed to the rubber layer 1 and the hard material layer 2, so that the spring constant in the longitudinal direction of the rectangular rubber bearing can be lowered. Since the rubber layer 3 has the same thickness as the rubber layer 1, the spring constant on the center side of the rubber bearing is considerably larger than when a recess is provided on one or both sides of the rubber layer 1 and the recess is filled with a soft rubber layer. As a result, the middle part of the rubber bearing can be easily compressed and deformed, so the difference in compressive stress between both sides of the rubber bearing in the longitudinal direction and the middle part can be considerably reduced, and the compressive stress in the rubber bearing can be made uniform. It is possible,
Therefore, the rectangular rubber bearing can be manufactured economically, and since it is only necessary to interpose the soft rubber layer 3 in the longitudinal middle of the rectangular rubber layer 1, the structure is simple and manufacturing is easy. The effect of this 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 plan view showing a rubber bearing for high reaction force according to the first embodiment of this invention, Fig. 5 is a partially cutaway enlarged sectional view thereof, and Fig. 6 is a high reaction force rubber bearing according to the second embodiment of this invention. FIG. 7 is a partially cutaway enlarged sectional view of the rubber bearing. In the figure, 1 is a rubber layer, 2 is a hard material layer, 3 is a soft rubber layer, and 4 is a rubber coating.

Claims (1)

[Scope of utility model registration request] In a rectangular rubber bearing in which hard material layers 2 are laminated on both sides of a rubber layer 1 and fixed together, a layer having the same thickness as the rubber layer 1 and softer than the rubber layer 1 is placed between the hard material layers 2. A soft rubber layer 3 made of a rubber material and extending between the middle portions of opposing long sides of the rubber bearing is interposed, and the soft rubber layer 3 is integrally fixed to the rubber layer 1 and the hard material layer 2. Rubber bearing for high reaction force featuring