JP2020159398A - Damping mechanism and base isolation structure - Google Patents

Abstract

To provide a damping mechanism capable of exhibiting damping force efficiently even in shaking of a large displacement such as a long-term earthquake, and a base isolation structure using the damping mechanism.SOLUTION: Since a rotational shaft 19 of a rotor is fixed to a base 7, the position of the rotor or the like does not change. When a base isolation floor 5 moves relative to the base 7, an intersection angle of arm members 11a, 11b changes. At this time, since a distance between a rotational shaft 13 and the rotational shaft 19 changes in each damping mechanism 3, the rotor moves relative to the arm members 11a, 11b. Along with the relative movement of the rotor and the arm members 11a, 11b, a rotary damper arranged on the rotor rotates. At this time, damping force is generated by the rotary damper.SELECTED DRAWING: Figure 4

Description

The present invention relates to a damping mechanism capable of efficiently dampening shaking and a seismic isolation structure using the damping mechanism.

Conventionally, as a countermeasure against an earthquake of a structure, there are a method of making the structure a rigid structure and a method of designing the structure so that the structure does not resonate with the shaking of an earthquake, as typified by a high-rise building. Such a method aims to prevent the structure itself from being destroyed by the shaking of an earthquake.

On the other hand, a seismic isolation structure that insulates the ground and the structure is drawing attention. According to the seismic isolation structure, the structure itself is insulated from the shaking of the ground, and the transmission of vibration to the structure can be suppressed.

Further, in the seismic isolation structure, since the part that sways with the ground and the part subject to seismic isolation are insulated, relative displacement occurs between them when an earthquake occurs. That is, in the event of an earthquake, a relative reciprocating motion occurs between the seismic isolated target portion and the surroundings. Therefore, it is necessary to attenuate this reciprocating operation.

As the damping mechanism of such a seismic isolation structure, for example, a hydraulic damper that exerts a damping force when the piston moves with respect to the cylinder is used (for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2014-114876

Hydraulic dampers are widely used as seismic isolation structures and vibration control structures because they can exert a large damping force and the damping force can be easily adjusted. However, if a general hydraulic damper is to be applied in order to exert a predetermined damping force in all directions of the seismic isolation floor, a large installation space is required. For example, it is necessary to arrange a large number of large hydraulic dampers around the seismic isolation floor, and the dead space becomes large.

In addition, long-period ground motion countermeasures are required for the countermeasures against large earthquakes currently envisioned. However, in such a long-period earthquake, the relative displacement is extremely large, so that it is difficult to design a hydraulic damper. Further, since the hydraulic damper having a large displacement amount itself becomes large, the degree of freedom in the installation layout is low.

The present invention has been made in view of such a problem, and is a damping mechanism capable of efficiently exerting a damping force even in a large-displacement shaking such as a long-period earthquake, and a seismic isolation structure using the damping mechanism. The purpose is to provide.

The first invention for achieving the above-mentioned object is a damping mechanism used for a pair of relatively displaceable structures, and a pair of arm members rotatably connected to the one structure. A pair of rotating bodies arranged on the other structure and rotatable on substantially the same axis, and a rotating damper arranged on the rotating body are provided, and the pair of arm members is provided with the one structure. The intersection angle of each of the connecting portions can be changed, and the rotating bodies are arranged in the vicinity of the intersection of the pair of arm members and respond to the change in the angle of the pair of arm members. Therefore, it is relatively movable along the arm member, and the relative linear movement between the rotating body and the arm member is converted into the rotation of the rotating body by the rotation conversion mechanism, and the rotation is performed. It is a damping mechanism characterized by exerting a damping force by the rotating damper when the body rotates.

The rotation conversion mechanism may be a rack provided on the arm member and a pinion provided on the rotating body.

According to the first invention, the rotation conversion mechanism converts the relative linear movement between the arm member and the rotating body into the rotation of the rotating body, and the rotation of the rotating body is dampened by the rotating damper. It can exert a damping force against a large amount of shaking in all directions. At this time, since it is not necessary to arrange a plurality of large hydraulic dampers, the degree of freedom in layout is high.

Further, if the rotation conversion mechanism is a rack and pinion mechanism, the structure is simple and the linear motion between the members can be reliably converted into the rotational motion.

The second invention is a seismic isolation structure using the damping mechanism according to the first invention, which includes a base, a seismic isolation bed movable with respect to the base, and a spring member connected to the seismic isolation bed. And the damping mechanism connected to the seismic isolation bed, and the arm member is rotatably connected to one of the seismic isolation bed or the base, and the seismic isolation bed or the base is provided. The seismic isolation structure is characterized in that the rotation axis of the rotating body is arranged with respect to the other.

At least a pair of the damping mechanisms may be arranged so as to face each other of the seismic isolation floor.

At least a pair of the damping mechanisms may be arranged in the directions orthogonal to each other of the seismic isolation floor.

According to the second invention, a seismic isolation structure can be surely obtained with a simple structure. At this time, if a plurality of damping mechanisms are arranged according to the size of the seismic isolation floor and the required damping force, a desired damping force can be secured.

Further, for example, when the damping force of the damping mechanism depends on the displacement direction of the seismic isolation bed, the damping force in the predetermined direction can be increased by arranging the damping mechanisms so as to face each other in a predetermined direction. You can also. Further, by arranging the damping mechanisms so as to be orthogonal to each other, it is possible to exert the damping force substantially evenly in each direction.

According to the present invention, it is possible to provide a damping mechanism capable of efficiently exerting a damping force even for a large displacement shaking such as a long-period earthquake, and a seismic isolation structure using the damping mechanism.

The plan view which shows the seismic isolation structure 1. (A) is a side conceptual view showing the seismic isolation structure 1, and (b) is an enlarged view of part A of (a). FIG. 2B is a cross-sectional view taken along the line BB of FIG. 2B, showing the relative movement of the rotating body 25 and the arm member 11a. The figure which shows the reference state and the state which the seismic isolation floor 5 moved to one side from the reference state. The figure which shows the state which the seismic isolation floor 5 moved in the other direction from the reference state. The figure which shows the state which the seismic isolation floor 5 moved in the other direction from the reference state. The plan view which shows the seismic isolation structure 1a.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a plan view showing a seismic isolation structure 1 according to the present invention, FIG. 2A is a side conceptual view showing a seismic isolation structure 1, and FIG. 2B is FIG. 2A. ) Is an enlarged view of part A. The seismic isolation structure 1 is mainly composed of a damping mechanism 3, a seismic isolation floor 5, a spring member 9, and the like.

The seismic isolation floor 5 is installed on the base 7 which is a structure such as a building or a foundation, and is arranged on the support portion 6. The support portion 6 is composed of a sliding member, a ball bearing, or the like that can move horizontally with respect to the base 7. That is, the seismic isolation floor 5 is a structure that can move relative to the base 7 that is the edge cutting target portion in the horizontal direction. Further, the seismic isolation floor 5 is connected to the base 7 by a damping mechanism 3 and a spring member 9.

The spring members 9 are arranged in a plurality of directions with respect to the seismic isolation floor 5 and are balanced with each other at reference positions. That is, the spring member 9 is a member for applying a force in the direction of returning the seismic isolation floor 5 to the reference position when the seismic isolation floor 5 deviates from the reference position of the base 7.

As shown in FIG. 2B, the damping mechanism 3 is used between the seismic isolation floor 5 and the base 7, and is a member that exerts a damping force when the seismic isolation floor 5 is relatively moved. The damping mechanism 3 is mainly composed of arm members 11a and 11b, a rotating body 25, a rotating damper and the like. In the illustrated example, at least a pair of damping mechanisms 3 are arranged so as to face each other of the seismic isolation floor 5.

As shown in FIG. 1, one end side of each of the pair of arm members 11a and 11b is connected by the rotation shaft 13 of the seismic isolation floor 5. That is, the arm members 11a and 11b are rotatably connected to the seismic isolation floor 5, respectively. The crossing angles of the pair of arm members 11a and 11b can be changed by keeping the distance between the connecting portions (rotating shaft 13) with the seismic isolation floor 5 constant.

A rotating shaft 19 is fixed to the base 7, and a pair of rotating bodies 25 are arranged on the same rotating shaft 19. That is, the pair of rotating bodies 25 can rotate independently on substantially the same axis. The rotating body 25 is arranged near the intersection of the pair of arm members 11a and 11b.

FIG. 3A is a cross-sectional view taken along the line BB of FIG. Note that FIG. 3A shows the arm member 11a, but the same applies to the arm member 11b. A rotating damper 26 is arranged on the rotating body 25. The rotary damper 26 can rotate around the rotation shaft 19 together with the rotating body 25, and when rotating, a damping force is generated by the rotation resistance.

Here, the arm members 11a and 11b have a frame shape in which a hollow portion 17 is formed inside in a portion other than the rotation shaft 13, and a rack 15 is formed on the inner surface side along the longitudinal direction. A pinion 27 is provided on the outer circumference of the rotating body 25. The rack 15 and the pinion 27 mesh with each other. That is, the rack of the arm member 11a and the pinion 27 of one rotating body 25 mesh with each other, and the rack of the arm member 11b and the pinion 27 of the other rotating body 25 mesh with each other.

As described above, the pair of arm members 11a and 11b can rotate with respect to the seismic isolation floor 5, respectively. When the seismic isolation floor 5 moves with respect to the base 7, the crossing angles of the arm members 11a and 11b change. FIG. 3B is a diagram showing a state in which the angle of the arm member 11a with respect to the rotating body 25 has changed from the state of FIG. 3A. As shown in FIG. 3B, when the angle of the arm member 11a with respect to the rotating body 25 changes (arrow C in the figure), the relative positions of the arm member 11a and the rotating body 25 change accordingly. For example, when the arm member 11a moves relative to the rotating body 25 in the arrow E direction, the rotating body 25 rotates in the arrow F direction due to the engagement between the rack 15 and the pinion 27.

In this way, when the seismic isolation floor 5 moves with respect to the base 7, the rotating body 25 is relatively movable along the arm members 11a and 11b. That is, the rotating body 25 moves linearly relative to the arm members 11a and 11b. On the other hand, since the rack 15 of the arm members 11a and 11b and the pinion 27 of the rotating body 25 mesh with each other, the relative movement of the rotating body 25 and the arm members 11a and 11b is converted into the rotation of the rotating body 25. That is, the rack 15 of the arm members 11a and 11b and the pinion 27 of the rotating body 25 are rotation conversion mechanisms that convert the relative linear movement between the rotating body 25 and the arm members 11a and 11b into the rotation of the rotating body 25. Functions as.

As shown in FIG. 2B, guide boards 21 that can rotate independently of the rotating body 25 are arranged above and below the rotating body 25, and a plurality of guide rollers are placed between the guide boards 21. 23 is arranged. As shown in FIG. 3A, the guide roller 23 comes into contact with the outer surface of the arm members 11a and 11b and the inner surface of the hollow portion 17. As shown in FIG. 3B, when the angles of the arm members 11a and 11b change, the guide board 21 also follows the rotation of the arm members 11a and 11b (arrow D in the figure). Therefore, the guide roller 23 always comes into contact with a part of the arm members 11a and 11b. As a result, the relative movement between the arm members 11a and 11b and the rotating body 25 becomes smooth, and the rack 15 and the pinion 27 can be reliably meshed with each other.

Next, the operation of the seismic isolation structure 1 will be described. The left figure of FIG. 4 is a diagram showing a state in which the seismic isolation floor 5 is located at a reference position with respect to the base 7. In the following figure, the illustration of the spring member 9 is omitted. At the reference position, the forces of the spring member 9 from each direction are balanced.

The right figure of FIG. 4 is a diagram showing a state in which the seismic isolation floor 5 is moved upward in the figure (in the direction of arrow H in the figure) from the reference position. As described above, since the rotating shaft 19 of the rotating body 25 (see FIG. 3) is fixed to the base 7, the position of the rotating body 25 and the like does not change (referred to as the reference position G in the vertical direction in the drawing). When the seismic isolation floor 5 moves relative to the base 7, the intersection angles of the arm members 11a and 11b fluctuate.

For example, in the upper damping mechanism 3 in the drawing, the arm members 11a and 11b rotate so that the crossing angle with each other becomes large, and in the lower damping mechanism 3 in the drawing, the arm members 11a and 11b rotate with each other. Rotate so that the crossing angle of is small. At this time, since the distance between the rotating shaft 13 and the rotating shaft 19 changes in each damping mechanism 3, the rotating body 25 moves relative to the arm members 11a and 11b.

As described above, the rotating damper 26 (see FIG. 3) arranged on the rotating body 25 rotates with the relative movement of the rotating body 25 and the arm members 11a and 11b. At this time, a damping force is generated by the rotary damper 26. Further, from the state shown on the right side of FIG. 4, the spring member 9 applies a force for returning to the reference position (left figure of FIG. 4). When the seismic isolation floor 5 returns to the reference position, the rotating body 25 moves relative to the arm members 11a and 11b, and the rotating damper 26 (see FIG. 3) arranged on the rotating body 25 rotates. At this time, a damping force is generated by the rotary damper 26.

In this way, when the seismic isolation bed 5 moves from the reference position, the damping mechanism 3 can generate a damping force when moving and returning to the original position.

The moving direction of the seismic isolation floor 5 is not particularly limited. For example, the example shown in FIG. 5 is a diagram showing a state in which the seismic isolation floor 5 is moved from the reference position (I in the figure) to the right direction (arrow J direction in the figure). That is, it is a figure which shows the state which the seismic isolation bed 5 moved in the direction perpendicular to the moving direction of FIG.

Even in this case, in each of the damping mechanisms 3, the crossing angles of the arm members 11a and 11b change, and the distance between the rotating shaft 13 and the rotating shaft 19 changes. Therefore, the rotating body 25 has the arm members 11a and 11b. Move relative to. Further, the rotating damper 26 arranged on the rotating body 25 rotates with the relative movement of the rotating body 25 and the arm members 11a and 11b. At this time, a damping force can be generated by the rotary damper 26.

Similarly, the example shown in FIG. 6 is a diagram showing a state in which the seismic isolation floor 5 has moved from the reference position (I in the figure) in the oblique direction (in the direction of arrow K in the figure). That is, it is a figure which shows the state which the seismic isolation bed 5 moved at a predetermined angle θ (0 <θ <90) with respect to the moving direction of FIG.

Even in this case, in each of the damping mechanisms 3, the crossing angles of the arm members 11a and 11b change, and the distance between the rotating shaft 13 and the rotating shaft 19 changes. Therefore, the rotating body 25 has the arm members 11a and 11b. Move relative to. Further, the rotating damper 26 arranged on the rotating body 25 rotates with the relative movement of the rotating body 25 and the arm members 11a and 11b. At this time, a damping force can be generated by the rotary damper 26.

As described above, according to the present embodiment, since the damping mechanism 3 is installed on the seismic isolation floor 5, the damping force can be generated when the seismic isolation floor 5 moves relative to the base 7. ..

At this time, since the damping mechanism 3 exerts a damping force by the relative movement of the arm members 11a and 11b and the rotating body 25, it has a simpler structure than the hydraulic damper and can handle a larger displacement swing. Can be made to. Therefore, it is possible to exert a sufficient damping force even for a long-period earthquake that vibrates in a low speed region.

Although details are omitted, when the seismic isolation structure 1 as shown in FIG. 1 was actually created and the damping force was measured, all directions (the moving direction shown in FIG. 4 was set to 0 degrees, and FIG. 5 shows. When the indicated moving direction was 90 degrees, sufficient damping force could be exhibited at 0 degrees, 30 degrees, 45 degrees and 90 degrees). Further, the larger the amplitude or frequency, the larger the damping force. The direction in which the largest damping force is exerted is when the moving direction is 0 degrees.

The rotation conversion mechanism that converts the relative linear movement of the rotating body 25 and the arm members 11a and 11b into the rotation of the rotating body 25 is not limited to the rack 15 and the pinion 27. For example, the mechanism is not particularly limited as long as the rotating body 25 rotates with the relative linear movement of the rotating body 25 and the arm members 11a and 11b, such as a chain and a sprocket.

Further, one damping mechanism 3 may be arranged with respect to the seismic isolation floor 5, or three or more damping mechanisms 3 may be arranged. Further, when the damping mechanisms 3 are arranged at a plurality of places, they may be arranged not only in the directions facing each other but also in the directions orthogonal to each other.

FIG. 7 is a plan conceptual diagram showing the seismic isolation structure 1a. In the seismic isolation structure 1a, a pair of damping mechanisms 3 are arranged in a direction orthogonal to each other with respect to the seismic isolation floor 5. In this way, when a plurality of damping mechanisms 3 are arranged with respect to the seismic isolation floor 5, at least a pair of damping mechanisms 3 may be arranged in the directions facing each other of the seismic isolation floors 5, or in the directions orthogonal to each other of the seismic isolation beds 5. At least one pair may be arranged.

Further, in the above-described embodiment, the arm members 11a and 11b are connected to the seismic isolation floor 5, and the rotating shaft 19 of the rotating body 25 is fixed to the base 7, but the present invention is not limited to this. For example, the arm members 11a and 11b may be connected to the base 7 and the rotating shaft 19 of the rotating body 25 may be fixed to the seismic isolation floor 5.

Further, the damping mechanism 3 can be applied to other than the seismic isolation structure. That is, by connecting the arm members 11a and 11b to one structure and arranging the rotating body 25 in the other structure with respect to the pair of relatively displaceable structures, the pair of structures can be connected to each other. A damping force can be generated with the displacement.

Although the embodiment of the present invention has been described above with reference to the attached drawings, the technical scope of the present invention does not depend on the above-described embodiment. It is clear that a person skilled in the art can come up with various modifications or modifications within the scope of the technical ideas described in the claims, and these are naturally within the technical scope of the present invention. It is understood that it belongs.

1, 1a ………… Seismic isolation structure 3 ………… Damping mechanism 5 ………… Seismic isolation floor 6 ………… Support 7 ………… Base 9 ………… Spring members 11a, 11b ………… Arm members 13 …… … Rotating shaft 15 ……… Rack 17 ……… Hollow part 19 ……… Rotating shaft 21 ……… Guide board 23 ……… Guide roller 25 ……… Rotating body 26 ……… Rotating damper 27 ……… Pinion

Claims (5)

A damping mechanism used for a pair of relatively displaceable structures.
A pair of arm members rotatably connected to one structure,
A pair of rotating bodies arranged on the other structure and rotatable on substantially the same axis,
A rotating damper arranged on the rotating body and
Equipped with
The pair of arm members can change the angle of intersection with each other while keeping the distance between the connection portions with one structure constant.
The rotating body is arranged near the intersection of the pair of arm members, and can move relatively along the arm members in response to a change in the angle of the pair of arm members.
The relative linear movement between the rotating body and the arm member is converted into the rotation of the rotating body by the rotation conversion mechanism, and when the rotating body rotates, the rotating damper exerts a damping force. Characteristic damping mechanism. The damping mechanism according to claim 1, wherein the rotation conversion mechanism is a rack provided on the arm member and a pinion provided on the rotating body. A seismic isolation structure using the damping mechanism according to claim 1 or 2.
With the base
A seismic isolation floor that can be moved with respect to the base,
The spring member connected to the seismic isolation floor and
With the damping mechanism connected to the seismic isolation floor,
Equipped with
The arm member is rotatably connected to one of the seismic isolation floor and the base.
A seismic isolation structure characterized in that a rotation axis of the rotating body is arranged with respect to the seismic isolation floor or the other of the base. The seismic isolation structure according to claim 3, wherein at least a pair of damping mechanisms are arranged so as to face each other of the seismic isolation floor. The seismic isolation structure according to claim 3 or 4, wherein at least a pair of damping mechanisms are arranged in a direction orthogonal to each other of the seismic isolation floor.

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