JPH0689800B2 - Vibration energy absorber - Google Patents

Description

Description: TECHNICAL FIELD OF THE INVENTION The present invention relates to a vibration energy absorbing device used for vibration isolation or seismic isolation of a structure, and in particular, it absorbs vibration energy by utilizing plastic deformation of a material. The present invention relates to the improvement of the vibration energy absorbing device.

[Technical background of the invention and its problems]

Conventionally, in order to prevent a structure from being destroyed by seismic force, for example, various types of vibration energy absorbing devices have been inserted between a foundation and a structure body.

Such vibration energy absorbers are classified according to the energy absorption mechanism. One is a viscous type that uses the viscosity of a fluid or a viscoelastic body, and the other is a friction type that uses the friction of materials. It is roughly divided into the plastic type using.

Among the above-mentioned vibration energy absorbers, many adopt the plastic method, and utilize the plastic deformation of the metal material.
Compared to other systems, it has the advantages of simple structure and low cost. Iron, lead, or lead-based alloy materials are usually used as elasto-plastic members that are directly used for energy absorption. Of these, the lead-based materials are particularly excellent in flexibility and have sufficient tracking characteristics even for vibrations involving large displacements.

By the way, the conventional vibration energy absorbing device utilizing the elasto-plastic characteristic due to the shear deformation of the material is generally shown in FIGS.
It is constructed as shown in FIG. That is, as shown in FIG. 4, the fixing plates 3 and 4 are fixed to the members 1 and 2 of the two target structures, respectively, so that they face each other. The structure is such that an elasto-plastic member 5 formed by processing the material into a cylindrical shape is inserted. The fixing plates 3 and 4 and the elasto-plastic member 5 are joined by brazing or the like. Also, the one shown in FIG.
Both ends of the elastic-plastic member 5 are recesses formed in the fixing plates 3 and 4, respectively.
The elasto-plastic member 5 and the respective fixing plates 3 and 4 are connected to each other by fitting them into 6, 7. Furthermore, the 7th
In the figure, an elastic support for supporting the member 2 with respect to the member 1, for example, a rubber bearing 8 is interposed between the fixing plates 3 and 4, and a through hole 9 extending in the axial direction is formed in the rubber bearing 8. The through hole 9 accommodates the elasto-plastic member 5 wound by the spiral coil 10 having a rectangular cross section. The rubber bearing 8 is formed by alternately laminating and joining metal plates 11 and rubber plates 12.

In these vibration energy absorbing devices, when a structure vibrates due to an earthquake or the like and relative displacement occurs between the members 1 and 2, the elasto-plastic member 5 existing between the members 1 and 2 is forcedly displaced. receive. At this time, when the elasto-plastic member 5 is plastically deformed, an energy loss equal to the amount of work required for the plastic deformation is generated, and as a result, the vibration energy between the members 1 and 2 is absorbed and the vibration response of the entire structure is reduced. To be done.

However, the conventional vibration energy absorbing device configured as described above has the following problems.

That is, in the structure shown in FIGS. 4 and 5, when the elastic-plastic member 5 is repeatedly deformed in the lateral direction by the relative displacement of the members 1 and 2 in the lateral direction in the drawings, the fixing plates 3 and 4 are Due to the difference in bending and tension between the portions near the fixing plates 3 and 4 and the central portion due to the local restraint between the elasto-plastic member 5 and the elasto-plastic member 5, As shown in the figure, the portion X close to the fixed plates 3 and 4 is constricted, and the central portion Y is swollen. For this reason, the resistance required for plastic deformation gradually decreases, and the energy absorption capacity decreases. Finally, there was a problem that the elasto-plastic member 5 was broken at the constricted portion and the function as the energy absorbing device was lost. On the other hand, in the structure shown in FIG. 7, since the spiral coil 10 is wound around the outer circumference of the elasto-plastic member 5, there are few problems as explained in FIG. However, with such a structure, since the elasto-plastic member 5 is housed in the rubber bearing 8 which is a support material of the structure,
The maintenance or replacement of the entire energy absorbing device becomes very troublesome, and there is a problem that it is not possible to promptly deal with weakening of the seismic resistance due to deterioration of the energy absorbing performance of the elastic-plastic member 5. That is, when the elasto-plastic member 5 repeatedly undergoes plastic deformation due to several earthquakes or vibrations, the structure of the elasto-plastic member 5 changes and the energy absorption capacity decreases. Therefore, in general, it is necessary to inspect the entire energy absorbing device and replace it if it has a predetermined characteristic or less. Without such replacement, the specified earthquake resistance and reliability will not be obtained in the case of the next earthquake, and the safety of the structure will be seriously affected. However, with the structure shown in FIG. 7, since the entire energy absorbing device is located inside the rubber bearing 8, the characteristics of the energy absorbing device cannot be easily inspected. Therefore, there is a possibility that the replacement timing may be wrong. Further, in order to restrain the radial deformation of the elasto-plastic member 5 and allow the shear deformation, the spiral coil 10 having a rectangular cross section is wound around the outer periphery of the elasto-plastic member 5. Then, when the elasto-plastic member 5 is deformed by the relative deformation force due to the relative displacement between the members 1 and 2,
The spiral coil 10 also undergoes relative deformation between the respective coils. In this case, since the spiral coil 10 is continuous, a twisting force acts on the spiral coil 10.
As described above, since the spiral coil 10 receives the radial deformation force of the elasto-plastic member 5, an excessive force, which is the sum of this force and the above-mentioned twisting force, eventually acts on the spiral coil 10. As a result, the spiral coil 10 may be broken. If it breaks, the restraining force against the radial deformation disappears, and the same problems as those of the device shown in FIGS. 4 and 5 occur. Also, what can be said in common with those in FIGS. 4, 5, and 7 is that when an earthquake such that the relative displacement between members 1 and 2 becomes extremely large,
This is a point that the elasto-plastic member 5 may be destroyed beyond the allowable displacement amount, or the load supporting member may be destroyed. When such a failure occurs, it poses a serious risk to the entire structure.

[Object of the Invention]

The present invention has been made in view of such circumstances, and an object thereof is to maintain the energy absorbing function of an elasto-plastic member provided for energy absorption for a longer period of time and to perform maintenance. Easy to inspect or replace,
Moreover, it is an object of the present invention to provide a vibration energy absorbing device capable of reliably preventing breakage of an elastic-plastic member, a load supporting member, and the like.

[Outline of Invention]

According to the present invention, first and second fixing plates respectively supported by two members capable of relative displacement, and a plastic elasto-plastic member inserted between the first and second fixing plates. And a plurality of materials having greater material strength and rigidity than the elasto-plastic member mounted on the outer periphery of the elasto-plastic member in close contact with the outer peripheral surface of the elasto-plastic member in a laminated state in the axial direction and slidably in the radial direction. Provided is a vibration energy absorbing device including a ring and an engaging portion which is provided in each of the rings so that adjacent ones are loosely fitted to each other and restricts a relative movement of the adjacent rings in a radial direction to a certain value or less. To be done.

〔The invention's effect〕

When an oscillating force that causes relative displacement between the two members is applied, such as an earthquake, the elasto-plastic member repeatedly undergoes plastic deformation according to the relative displacement amount between the two members. At this time,
The elasto-plastic member is acted on by a force that forms a constriction at both ends and a bulge at the center. However, since the rings are attached to the outer periphery of the elasto-plastic member in the above relationship, these rings slide with each other to allow the shear deformation of the elasto-plastic member, but restrain the radial deformation of the elasto-plastic member to restrict the constriction or Prevents bulging. In this way, it is possible to prevent the constriction from occurring at both ends of the elasto-plastic member, so that it is possible to prevent the elasto-plastic member from breaking with a small number of repetitions due to the constriction, and in the long run As a result, the elastic-plastic member can be made to exhibit a good energy absorbing function. In this case, since each ring is independent in the axial direction, when the elasto-plastic member is plastically deformed, almost no force other than the radial deformation force of the elasto-plastic member is applied to each ring. Therefore, as a result, the strength of each ring can be increased and the life can be further extended. Further, since the rings are mounted in a stacked state in the axial direction, that is, in a state where there is almost no gap between the rings, part of the elasto-plastic member does not flow out from between the rings during plastic deformation. In addition, since each ring is provided with an engaging part that allows the adjacent ones to loosely fit together and regulates the relative amount of radial movement of the adjacent rings to a certain value or less, large displacement between members Even if an error occurs, the displacement is constrained by the allowable movement amount set between the rings, that is, the total displacement of the adjacent rings. Therefore, by setting the above-mentioned constrained displacement in advance to the allowable displacement amount of the elasto-plastic member, the load supporting member, etc., it is possible to prevent the elasto-plastic member from breaking or the load supporting member from breaking during a large earthquake. It is possible to avoid a serious influence on the structure caused by the destruction. Furthermore, since it can be installed independently of other elements, it becomes easy to inspect the current state and characteristics of the elasto-plastic member after the earthquake, and as a result, it is possible to contribute to the prevention of error in the replacement timing. . Further, since it can be installed independently of other devices, for example, a load bearing device such as a rubber bearing, it can contribute to facilitating the replacement of the device.

Example of Invention

 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a side view of an example in which a vibration energy absorbing device according to an embodiment of the present invention is actually installed between two members 21 and 22 of a structure. That is, in this energy absorbing device, the fixing plates 23 and 24 are fixed to the members 21 and 22 by a bolt or the like (not shown) so as to face each other, and
An elasto-plastic member formed between 3 and 24 in a columnar shape, for example, with lead
25 are inserted. Then, the elastic-plastic member 25 and each fixing plate 2
3,24 are joined by brazing, for example.

On the outer periphery of the elasto-plastic member 25, a plurality of rings 26 are attached in close contact with the outer peripheral surface of the elasto-plastic member 25 and in a stacked state in the axial direction. In the case of this embodiment, these rings 26 are made of iron having a tensile strength higher than that of lead forming the elasto-plastic member 25.
The elasto-plastic member 5 is formed so as to be able to resist the radial deformation force. Each ring 26
Each of the ring body 27 is in direct contact with the outer peripheral surface of the elasto-plastic member 25, the portion 28 protruding outward from one end side of the ring body 27, and the axis of the ring body 27 from the tip of this portion 28. It is composed of a projecting peripheral wall 29 extending in parallel and in a direction projecting from the end surface of the ring body 27. As shown in FIG. 1, the rings 26 configured as described above are stacked with the protruding directions of the protruding peripheral walls 29 aligned with each other and mounted on the outer periphery of the elastic-plastic member 25. Therefore, the inner peripheral surface of the protruding peripheral wall 29 of the ring 26 located in the lower stage and the ring located in the upper stage
Predetermined gaps 30 are formed between the outer peripheral surfaces of the ring bodies 27 of 26. The ring 26 located at the lowermost stage is fixed to the fixed plate 23, and the ring 26 located at the uppermost stage is fixed to the fixed plate 24. In this embodiment, as the ring 26 located at the uppermost stage, the ring 28 with the portion 28 and the peripheral wall 29 omitted is used.

With such a configuration, when a relative displacement in the lateral direction in the figure occurs between the members 21 and 22 due to an earthquake or the like, each ring 26 slides in the radial direction, and the elasto-plastic member 25 becomes as shown in FIG. Receive repeated deformation. Therefore, energy consumption required for plastic deformation occurs in the elasto-plastic member 25, and the function as a vibration energy absorbing device is exerted by this energy consumption.

In this case, even if the elastic-plastic member 25 has a constricted portion or a bulging portion due to repeated deformation, the generated force is suppressed by the rings 26, so that the constricted portion or the bulged portion is eventually generated. Suppressed. Thus, in particular,
Since it is possible to prevent the occurrence of constrictions at both ends of the elasto-plastic member 25, it is possible to prevent the elasto-plastic member 25 from breaking with a small number of repetitions, and it is possible to exert the energy absorbing function satisfactorily for a long period of time. . Further, since each ring 26 is laterally independent, when the elasto-plastic member 25 is plastically deformed, no force other than the radial deformation force of the elasto-plastic member 25 is applied to each ring 26. Therefore, the strength of the ring 26 can be increased as a result, and the life can be further extended, as compared with the case where the spiral coil is used as the deformation preventing member. Further, since the rings 26 are mounted in a stacked state in the axial direction, that is, in a state where there is almost no gap between the rings, an elasto-plastic member is inserted between the rings during plastic deformation.
A part of 25 does not flow out. Further, when the relative displacement between the members 21 and 22 exceeds a certain value due to the arrival of a large earthquake or the like, as shown in FIG. 3, in one direction, the lower peripheral wall 29 and the upper ring body 27 of the peripheral wall 29 are located. The gap 30 between the ring body 27 and the protruding wall 29 is adjacent to the ring body 27.
Further engagement is prevented by the engagement action with. Therefore, if the total sum of the gaps 30 is set to an appropriate allowable displacement amount of the elasto-plastic member 25 or the allowable displacement amount of the load supporting member provided between the members 21 and 22, for example, within the above allowable variable amount. Vibration energy can be absorbed by the plastic deformation of the elasto-plastic member 25 at the time of displacement, and the ring main body 27
It is possible to prevent the elasto-plastic member 25 and the load supporting member from being destroyed by forcibly restraining the displacement to the allowable displacement amount by the engaging action of the protrusion and the circumferential wall 29. Also, when this energy absorbing device is actually installed, it can be installed independently of other elements. Therefore, when the earthquake has subsided, it is possible to quickly perform inspections, characteristic inspections, etc., which also contributes to prevention of incorrect replacement timing. Furthermore, since it can be installed independently of other elements, it can contribute to facilitation of replacement, and in the end, the above-mentioned effects can be exhibited.

It should be noted that the present invention is not limited to the above-mentioned embodiments, but can be variously modified. That is, in the above-described embodiment, both end surfaces of the elasto-plastic member 25 are fixed to the fixing plates 23 and 24 by brazing or the like. However, the fixing plates 23 and 24 are provided with recesses, and these recesses are elastic-plastic. The member 25 and both ends,
The fixing plates 23 and 24 may be joined to both ends of the elasto-plastic member 25 and the rings located at both ends by being fitted integrally with the rings attached to the outer peripheries of both ends. By doing so, the connection between the two can be made stronger and the reliability of the device can be improved. Further, the shape of the elasto-plastic member 25 is not limited to a cylindrical shape and may be a prismatic shape, and the diameter and length thereof are the total number when the energy absorbing device is actually installed, the mass of the target structure, and the rigidity of the structure. Of course, it depends on the required energy absorption amount and the plastic characteristics of the elasto-plastic member used. Further, the material forming the elasto-plastic member is not limited to lead, and it is needless to say that a lead alloy, iron or the like can be used. Further, although the load supporting means is not particularly mentioned in the above-mentioned embodiment, when a load supporting mechanism that contracts during load supporting including vibration deformation such as a rubber bearing is used, either one of the two fixing plates and this is used. A means for absorbing the contraction, such as an elastic mechanism, may be interposed between the member to be supported and a gap corresponding to the contraction may be provided.

[Brief description of drawings]

FIG. 1 is a side view showing a partially cutaway example of a vibration energy absorbing device according to an embodiment of the present invention when it is actually installed between two members, and FIG. 2 shows the energy absorbing operation of the device. Fig. 3 is a cross-sectional view of the conventional vibration energy absorbing device, Fig. 3 is a cross-sectional view of the same device performing displacement restraining operation, and Figs. 4 and 5 are vertical cross-sectional views of a conventional vibration energy absorbing device. FIG. 7 is a diagram for explaining the problems of the conventional device, and FIG. 7 is a vertical sectional view of still another example of the conventional vibration energy absorbing device. 21, 22 ... Member, 23, 24 ... Fixing plate, 25 ... Elasto-plastic member, 26 ... Ring, 29 ... Projection peripheral wall that functions as an engaging portion for restraining displacement.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Satoshi Otoshi Komukai Toshiba Town No. 1, Komukai-shi, Kawasaki City, Kanagawa Prefecture Inside the Toshiba Research Institute Co., Ltd. (56) Reference JP-A-52-49609 (JP, A) Actual Kai 54-136489 (JP, U)

Claims (2)

[Claims] 1. A first and a second fixing plate for absorbing kinetic energy during relative movement between two members, which are respectively supported by the respective members, and the first and second fixing plates. And a plastic elasto-plastic member inserted between the fixing plates, and mounted on the outer periphery of the elasto-plastic member in a laminated state in the axial direction and slidably in the radial direction by closely contacting the outer peripheral surface of the elasto-plastic member. The plurality of rings having a material strength and rigidity higher than that of the elasto-plastic member and the adjacent ones are loosely fitted to each other, and the relative movement in the radial direction of the adjacent rings is set to a certain value or less. A vibration energy absorbing device, comprising: an engaging portion that regulates the vibration energy. 2. The vibration energy absorbing device according to claim 1, wherein the elasto-plastic member is formed of one kind selected from lead, a lead-based alloy and iron. apparatus.