JP7210351B2 - Damping mechanism and seismic isolation structure - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a damping mechanism capable of efficiently damping shaking and a seismic isolation structure using the same.

2. Description of the Related Art Conventionally, as countermeasures against earthquakes, etc., for structures, there are a method of making the structure a rigid structure, and a method of designing the structure so that it does not resonate against the shaking of an earthquake, as typified by high-rise buildings. Such a method aims at preventing 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 attracting attention. According to the seismic isolation structure, the structure itself is insulated from shaking of the ground, and transmission of vibration to the structure can be suppressed.

In addition, in the seismic isolation structure, since the part that shakes with the ground and the part to be seismically isolated are insulated, relative displacement occurs between them when an earthquake occurs. In other words, during an earthquake, a relative reciprocating motion occurs between the part to be seismically isolated and the surroundings. Therefore, there is a need to dampen this reciprocating motion.

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

JP 2014-114867 A

Hydraulic dampers are widely used as seismic isolation structures and vibration damping structures because they can exert a large damping force and can easily adjust the damping force. However, applying a general hydraulic damper to exert a predetermined damping force in all directions of the seismic isolation floor requires a large installation space. For example, many large hydraulic dampers need to be arranged around the seismic isolation floor, resulting in a large dead space.

In addition, countermeasures against long-period seismic ground motions are necessary for countermeasures against huge earthquakes that are currently assumed. However, it is difficult to design a hydraulic damper for such a long-period earthquake because the relative displacement is extremely large. Moreover, a hydraulic damper having a large amount of displacement is itself large in size, and therefore has a low degree of freedom in the layout of installation.

The present invention has been made in view of such problems. intended to provide

A first invention for achieving the above object is a damping mechanism used for a pair of relatively displaceable structures, comprising a pair of arm members rotatably connected to one of the structures, and , a pair of rotating bodies arranged on the other structure and rotatable on substantially the same axis; and a rotary damper arranged on the rotating bodies, wherein the pair of arm members and the one structure are provided. The intersecting angle of each of the connecting portions is fixed and the intersecting angle can be changed. relative linear movement between the rotating body and the arm member is converted into rotation of the rotating body by a rotation conversion mechanism; The damping mechanism is characterized in that a damping force is exerted by the rotary 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 converting mechanism converts the relative linear movement between the arm member and the rotating body into rotation of the rotating body, and the rotation of the rotating body is damped by the rotation damper. A damping force can be exerted even for large amounts of shaking in all directions. In this case, since it is not necessary to arrange a plurality of large hydraulic dampers, there is a high degree of freedom in layout.

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

A second invention is a seismic isolation structure using the damping mechanism according to the first invention, comprising a base, a seismic isolation floor movable with respect to the base, and a spring member connected to the seismic isolation floor. and the damping mechanism connected to the seismic isolation floor, wherein the arm member is rotatably connected to either the seismic isolation floor or the base, and the seismic isolation floor or the base and the rotating shaft of the rotating body is disposed on the other side of the base isolation structure.

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

At least one pair of damping mechanisms may be arranged on the seismic isolation floor in mutually orthogonal directions.

According to the second invention, it is possible to reliably obtain a seismic isolation structure with a simple structure. At this time, a desired damping force can be secured by arranging a plurality of damping mechanisms according to the size of the seismic isolation floor and the required damping force.

Further, for example, when the damping force of the damping mechanism depends on the displacement direction of the seismic isolation floor, the damping force in a predetermined direction can be increased by arranging the damping mechanism so as to face each other in a predetermined direction. can also Further, by arranging the damping mechanisms so as to be perpendicular to each other, damping forces can be exerted substantially equally in each direction.

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

FIG. 2 is a conceptual plan view showing the seismic isolation structure 1; (a) is a conceptual side 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 between the rotor 25 and the arm member 11a; The figure which shows the state which the seismic isolation floor 5 moved to one side from the reference state and the reference state. The figure which shows the state which the seismic isolation floor 5 moved to the other direction from the reference state. The figure which shows the state which the seismic isolation floor 5 moved to another direction from the reference state. The plane conceptual diagram which shows the seismic isolation structure 1a.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail based on the drawings. FIG. 1 is a conceptual plan view showing a base isolation structure 1 according to the present invention, FIG. 2(a) is a side conceptual view showing the base isolation structure 1, and FIG. ) is an enlarged view of part A of FIG. A 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 a base 7 , which is a structure such as a building or foundation, and arranged on a support section 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 . In other words, the seismic isolation floor 5 is a structure that is relatively movable in the horizontal direction with respect to the base 7 that is the part to be trimmed. Also, the seismic isolation floor 5 is connected to the base 7 by the damping mechanism 3 and the 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 the reference position. That is, the spring member 9 is a member for applying a force to the base isolation floor 5 in the direction of returning it to the reference position when the base isolation floor 5 deviates from the reference position of the base 7 .

As shown in FIG. 2B, the damping mechanism 3 is a member that is used between the seismic isolation floor 5 and the base 7 and exerts a damping force when the seismic isolation floor 5 moves relative to each other. 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 one pair of damping mechanisms 3 are arranged on the seismic isolation floor 5 so as to face each other.

As shown in FIG. 1 , one end sides of the pair of arm members 11 a and 11 b are connected to each other at a rotating 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 pair of arm members 11a and 11b can change the mutual crossing angle while keeping the distance between the connecting portions (rotating shafts 13) to 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 rotors 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. 3(a) is a cross-sectional view taken along line BB of FIG. Although FIG. 3A illustrates the arm member 11a, the same applies to the arm member 11b. A rotary damper 26 is arranged on the rotating body 25 . The rotary damper 26 is rotatable about the rotary shaft 19 together with the rotating body 25, and generates a damping force by rotational resistance when rotating.

Here, the arm members 11a and 11b have a frame shape with a hollow portion 17 formed inside at portions other than the rotating 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 rotor 25 . The rack 15 and pinion 27 mesh with each other. That is, the rack of the arm member 11a and the pinion 27 of one rotating body 25 are meshed, and the rack of the arm member 11b and the pinion 27 of the other rotating body 25 are meshed.

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

In this manner, when the seismic isolation floor 5 moves relative to the base 7, the rotor 25 can move relatively along the arm members 11a and 11b. That is, the rotor 25 moves linearly relative to the arm members 11a and 11b. On the other hand, since the racks 15 of the arm members 11 a and 11 b mesh with the pinions 27 of the rotating body 25 , relative movement between the rotating body 25 and the arm members 11 a and 11 b is converted into rotation of the rotating body 25 . That is, the rack 15 of the arm members 11a and 11b and the pinion 27 of the rotor 25 are a rotation conversion mechanism that converts relative linear movement between the rotor 25 and the arm members 11a and 11b into rotation of the rotor 25. function as

As shown in FIG. 2B, guide discs 21 rotatable independently of the rotator 25 are arranged above and below the rotator 25. Between the guide discs 21, a plurality of guide rollers are arranged. 23 are placed. As shown in FIG. 3( a ), the guide roller 23 contacts the outer surfaces of the arm members 11 a and 11 b 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 disc 21 also follows the rotation of the arm members 11a and 11b (arrow D in the figure). Therefore, the guide roller 23 is always in contact with part of the arm members 11a and 11b. As a result, relative movement between the arm members 11a and 11b and the rotor 25 becomes smooth, and the rack 15 and the pinion 27 can be reliably meshed.

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

The right diagram of FIG. 4 shows a state in which the seismic isolation floor 5 has moved upward in the diagram (in the direction of arrow H in the diagram) 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 positions of the rotating body 25 and the like do not change (the vertical reference position G in the figure). When the seismic isolation floor 5 moves relative to the base 7, the crossing angles of the arm members 11a and 11b change.

For example, in the damping mechanism 3 shown in the upper part of the drawing, the arm members 11a and 11b rotate so that the mutual crossing angle becomes large. rotate so that the crossing angle of 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 rotary damper 26 (see FIG. 3) arranged on the rotating body 25 rotates as the rotating body 25 and the arm members 11a and 11b move relative to each other. At this time, a damping force is generated by the rotary damper 26 . Further, from the state shown in the right diagram of FIG. 4, a force is applied by the spring member 9 to return to the reference position (left diagram of FIG. 4). Even 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 .

Thus, when the seismic isolation floor 5 moves from the reference position, the damping mechanism 3 can generate a damping force when moving and returning to the original position.

Note that 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 has moved rightward (direction of arrow J in the figure) from the reference position (I in the figure). That is, it is a diagram showing a state in which the seismic isolation floor 5 has moved in a direction perpendicular to the direction of movement in FIG.

Even in this case, in each damping mechanism 3, the crossing angle of the arm members 11a and 11b changes, and the distance between the rotating shaft 13 and the rotating shaft 19 changes. move relative to Further, the rotary damper 26 arranged on the rotating body 25 rotates with the relative movement between 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 obliquely (direction of arrow K in the figure) from the reference position (I in the figure). That is, it is a diagram showing a state in which the seismic isolation floor 5 moves at a predetermined angle θ (0<θ<90) with respect to the moving direction of FIG. 4 .

Even in this case, in each damping mechanism 3, the crossing angle of the arm members 11a and 11b changes, and the distance between the rotating shaft 13 and the rotating shaft 19 changes. move relative to Further, the rotary damper 26 arranged on the rotating body 25 rotates with the relative movement between 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 with respect to the seismic isolation floor 5, a 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 relative movement of the arm members 11a and 11b and the rotating body 25, it has a simpler structure than a hydraulic damper and can cope with larger displacement shaking. can be made Therefore, sufficient damping force can be exerted even for long-period earthquakes, which are vibrations in the low-velocity region.

Although the details are omitted, the seismic isolation structure 1 as shown in FIG. 1 was actually created and the damping force was measured. Sufficient damping force was able to be demonstrated at 0 degrees, 30 degrees, 45 degrees and 90 degrees when the movement direction shown was 90 degrees. Also, the greater the amplitude or frequency, the greater the damping force. It should be noted that the direction in which the greatest damping force was exhibited was when the moving direction was 0 degrees.

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

Also, one damping mechanism 3 may be arranged on 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 positions, they may be arranged not only in directions facing each other but also in directions perpendicular to each other.

FIG. 7 is a conceptual plan view showing the seismic isolation structure 1a. In the seismic isolation structure 1a, a pair of damping mechanisms 3 are also arranged on the seismic isolation floor 5 in directions perpendicular to each other. Thus, when a plurality of damping mechanisms 3 are arranged on the seismic isolation floor 5, at least one pair may be arranged on the seismic isolation floor 5 facing each other. 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 rotation shaft 19 of the rotor 25 is fixed to the base 7, but this is not restrictive. For example, the arm members 11 a and 11 b 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 .

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

Although the embodiments of the present invention have been described above with reference to the accompanying drawings, the technical scope of the present invention is not influenced by the above-described embodiments. It is obvious that a person skilled in the art can conceive various modifications or modifications within the scope of the technical idea described in the claims, and these are naturally within the technical scope of the present invention. be understood to belong to

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

Claims (5)

A damping mechanism for use in a pair of relatively displaceable structures, comprising:
a pair of arm members rotatably connected to one structure;
a pair of rotating bodies arranged in the other structure and rotatable on substantially the same axis;
a rotary damper arranged on the rotating body;
and
The pair of arm members can change the mutual crossing angle while keeping the distance between the respective connection parts with one structure constant,
the rotating body is disposed near the intersection of the pair of arm members and is relatively movable along the arm members according to a change in the angle of the pair of arm members;
A relative linear movement between the rotating body and the arm member is converted into rotation of the rotating body by a rotation conversion mechanism, and damping force is exerted by the rotating damper when the rotating body rotates. Characterized damping mechanism. 2. The damping mechanism according to claim 1, wherein the rotation converting 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 claim 2,
a base;
a seismic isolation floor movable with respect to the base;
a spring member connected to the seismic isolation floor;
the damping mechanism connected to the seismic isolation floor;
and
the arm member is rotatably connected to one of the seismic isolation floor and the base;
A seismic isolation structure, wherein the rotating shaft of the rotating body is arranged with respect to the other of the seismic isolation floor and the base. 4. The seismic isolation structure according to claim 3, wherein at least a pair of said damping mechanisms are arranged on said seismic isolation floor so as to face each other. 5. A seismic isolation structure according to claim 3, wherein at least one pair of said damping mechanisms are arranged in directions perpendicular to each other on said seismic isolation floor.

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