JPS6111289Y2 - - Google Patents

Description

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

Conventionally, as shown in Figures 1 and 2, rubber bearings for bridge bearings have been manufactured by laminating steel plates or other hard material layers 2 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
Since the load is limited to about 50 to 55 kg/cm ² , 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 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 size is 200mm square, the thickness of rubber layer 1
When a compressive load is applied to a rubber bearing with a thickness of 16mm, a hard material layer (steel plate) 2 is 1.6mm thick, and a rubber coating 4 is 3mm thick and the compressive stress distribution is examined, the results shown in Figure 3 are obtained. .

As can be seen from Figure 3, the peripheral edge S of the rubber bearing
The compressive stress increases rapidly from the center toward the center C, and the difference in the compressive stress increases as the area of the rubber bearing increases. Further, as mentioned above, the allowable compressive stress of the rubber layer is limited to about 50 to 55 kg/cm ² , 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 increased too much, it is not only uneconomical, but also has the problem that the shear resistance of the rubber layer when the bridge expands and contracts becomes excessive.

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 an embodiment of this invention, in which a through opening 5 is provided in the center of the rubber layer 1, and the through opening 5 has the same thickness as the rubber layer 1. A soft rubber layer 3 made of rubber that is larger in size and softer than the rubber layer 1 is filled, and the soft rubber layer 3 is in close contact with the entire circumferential surface of the through opening 5, and the soft rubber layer 3 is made of rubber that is softer than the rubber layer 1. A hard material layer 2 made of a steel plate and a rubber coating 4 are provided on the upper and lower surfaces, respectively.
are sequentially laminated, 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).

The rubber layer 1 has a hardness of about 60°, for example.
For example, the soft rubber layer 3 has a hardness of about 50° to 55°,
As the rubber coating 4, for example, one having a hardness of about 40° is used. 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 together, a through opening 5 is provided at the center of the rubber bearing in the rubber layer 1, and the through opening 5 is A soft rubber layer 3 having the same thickness as the rubber layer 1 and softer than the rubber layer 1 is filled in the opening 5.
is in close contact with the entire circumferential surface of the through opening 5, so when a load is applied to the rubber bearing, the spring constant on the central side of the rubber bearing is lower than the spring constant on the peripheral side of the rubber bearing. When a large load is applied to the bearing, the middle part of the soft rubber layer 3 in the center and the surrounding rubber layer 1 are allowed to elongate in the thickness direction. The spring constant of the rubber bearing can be kept low, and the difference in compressive stress between the peripheral and central parts of the rubber bearing can therefore be made considerably small, making it possible to economically manufacture rubber bearings for high reaction forces. Furthermore, since the soft rubber layer 3 has the same thickness as the rubber layer 1, the thickness of the central part of the rubber bearing is smaller than when a recess is provided on one or both sides of the rubber layer 1 and the recess is filled with the soft rubber layer. The spring constant can be made considerably low, and since it is only necessary to fill the through opening 5 in the center of the rubber layer 1 with the soft rubber layer 3, effects such as a simple structure and easy 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 sectional view of a portion thereof, and FIG. 3 is a diagram showing the compressive stress distribution state of a conventional rubber bearing. FIG. 4 is a plan view showing a rubber bearing for high reaction force according to an embodiment of the invention, and FIG. 5 is an enlarged sectional view taken along the line A--A. In the figure, 1 is a rubber layer, 2 is a hard material layer, and 3 is a rubber layer.
4 is a soft rubber layer, 4 is a rubber coating, and 5 is a through opening.

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 fixed together, a through opening 5 is provided in the center of the rubber bearing in the rubber layer 1, and a rubber layer is formed in the through opening 5. A high-reflection material characterized in that a soft rubber layer 3 having the same thickness as the layer 1 and softer than the rubber layer 1 is filled, and the soft rubber layer 3 is in close contact with the entire circumferential surface of the through opening 5. Rubber bearing for power.