JP2015010650A - Oil damper, and damper system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently add damping force to two relatively displacing members.SOLUTION: An oil damper is provided between two relatively displacing members to damp vibration of the two members and has: a first connection part connected to one of the two members; a second connection part connected to the other of the two members; a first oil housing part whose capacity decreases as distance from the first connection part to the second connection part becomes longer; a second oil housing part which communicates with the first oil housing part and whose capacity increases as the distance from the first connection part to the second connection part becomes longer; and oil movable between the first oil housing part and the second oil housing part when the two members relatively displace, and damping force to be generated with displacement lager than predetermined displacement is larger than damping force to be generated with displacement equal to or less than the predetermined displacement when the two members relatively displace in a direction that the first connection part and the second connection part separate from each other.

Description

  The present invention relates to an oil damper and a damper system.

  The floor of a room where precision equipment (such as a computer) is installed is a double floor structure in which a floor (hereinafter also referred to as a seismic isolation floor) is constructed above the floor of the building itself (hereinafter also referred to as a structural floor). A floor seismic isolation system has been developed in which seismic isolation devices are arranged between floors so as to be isolated from vibrations such as earthquakes (for example, see Patent Document 1).

  An oil damper is known as a device used in combination with a seismic isolation device. The oil damper is an attenuation member that attenuates vibration between two members that are relatively displaced using oil that is a viscous fluid (see, for example, Patent Document 2).

  By the way, in a long-period earthquake, the amount of displacement of the ground increases, and accordingly, the amount of relative displacement between the structural floor and the base isolation floor tends to increase. For this reason, it is conceivable to add an oil damper to the seismic isolation device as a floor seismic isolation system for such long-period earthquakes.

JP-A-6-33582 JP 2013-50174 A

  However, if an oil damper is added to the seismic isolation device, the damping force of the oil damper is always added to the seismic isolation device when displacement occurs due to an earthquake. For this reason, when the damping force of an oil damper is large, there exists a possibility that the performance which suppresses the response acceleration in a seismic isolation apparatus may fall. Conversely, when the damping force of the oil damper is small, it is difficult to suppress deformation when the displacement is large, and the base isolation floor collides with the fixed floor and damages the base isolation floor or equipment loaded on the base isolation floor. There is a risk. In addition, if the area | region of the clearance (buffer part) around a seismic isolation floor is expanded, such a collision can be prevented, but in this case, an effective floor area will become small. As described above, there is a problem in that a damping force cannot be efficiently applied to two members that are relatively displaced, such as a structural floor and a seismic isolation floor.

  The present invention has been made in view of such conventional problems, and its main object is to efficiently apply a damping force to two members that are relatively displaced.

In order to achieve this object, an oil damper according to the present invention is an oil damper that is provided between two members that are relatively displaced, and that attenuates vibrations of the two members. Capacity increases as the distance from the first connection part connected to the member, the second connection part connected to the other of the two members, and the first connection part to the second connection part increases. The first oil storage portion that decreases and the second oil storage portion that communicates with the first oil storage portion, and the capacity increases as the distance from the first connection portion to the second connection portion increases. A second oil storage section, and oil that can move between the first oil storage section and the second oil storage section when the two members are relatively displaced, and the first connection section. And the second connecting portion in a direction away from One of when the member is displaced relative damping force generated by the larger displacement than the predetermined displacement, and greater than the damping force generated by the predetermined displacement following the displacement.
According to such an oil damper, almost no damping force can be applied when the amount of displacement between the two members is small. In addition, when the amount of displacement is large, a large damping force can be applied to suppress deformation. Thus, it is possible to efficiently apply a damping force to the two members that are relatively displaced.

In such an oil damper, the damping force generated when the displacement is larger than the predetermined displacement is the damping generated when the two members are relatively displaced in the direction in which the first connection portion and the second connection portion approach each other. Desirably greater than force.
According to such an oil damper, it is possible to generate a large damping force only when the direction of relative displacement is only in one direction.

The oil damper is a cylinder having a hollow portion, and is provided so as to be movable in the axial direction in the hollow portion of the cylinder, and the hollow portion is moved to the first oil storage portion according to relative displacement of the two members. And a piston that is divided into the second oil storage portion, and a first flow path provided in the piston, allowing movement of the oil from the first oil storage portion to the second oil storage portion. A first flow path provided with a valve for prohibiting movement of the oil from the second oil storage section to the first oil storage section, and the piston, the first oil storage section and the second oil A second flow path that communicates with the accommodating portion, and the cylinder communicates between the first oil accommodating portion and the second oil accommodating portion when the relative displacement between the two members is equal to or less than the predetermined displacement. Let before When the relative displacement of the two members is greater than the predetermined displacement desirably has a notch for blocking the second oil containing portion and said first oil containing portion.
According to such an oil damper, it is possible to switch the damping force according to the amount of relative displacement between the two members.

In this oil damper, it is preferable that the flow path resistance of the second flow path is larger than the flow path resistance of the first flow path and the flow path resistance of the notch.
According to such an oil damper, it is possible to generate a larger damping force when the displacement amount is large.

Also, in the oil damper system using such an oil damper, two oil dampers are provided for the one member and the other member, and each oil damper generates a damping force in the opposite direction to each other. An oil damper system characterized by this will become apparent.
According to such an oil damper system, it is possible to efficiently suppress the displacement of the two members.

In such an oil damper system, it is desirable that the one member is a structural floor and the other member is a seismic isolation floor provided above the structural floor.
Such an oil damper system can be suitably applied to a seismic isolation device for a seismic isolation floor.

  According to the present invention, it is possible to efficiently apply a damping force to two members that are relatively displaced.

It is a top view which shows the floor seismic isolation system to which the oil damper of this embodiment was applied. 2A is an enlarged view of a corner portion (a portion including the seismic isolation unit 10b) in FIG. 1, and FIG. 2B is a cross-sectional view of FIG. 2A. FIG. 3A is an enlarged view of the seismic isolation unit 10a, and FIG. 3B is a cross-sectional view of FIG. 3A. 4A is an enlarged view of the seismic isolation unit 10c, and FIG. 4B is a cross-sectional view of FIG. 4A. It is sectional drawing which shows the structure of the oil damper 100 which concerns on this embodiment. It is the schematic of the XX cross section of FIG. 7A to 7G are diagrams for explaining the operation of the oil damper 100 of the present embodiment. FIG. 8A to FIG. 8C are explanatory diagrams about the damping operation of the oil damper 100 in the seismic isolation unit 10c.

=== Embodiment ===
<About the floor seismic isolation system>
FIG. 1 is a plan view showing a floor seismic isolation system to which the oil damper of this embodiment is applied. 2A is an enlarged view of a corner portion (a portion including the seismic isolation unit 10b) in FIG. 1, and FIG. 2B is a cross-sectional view of FIG. 2A. 2B shows a state in which the cross section along the large beam 3 in FIG. 2A is viewed from the side. 3A is an enlarged view of the seismic isolation unit 10a, and FIG. 3B is a cross-sectional view of FIG. 3A. 4A is an enlarged view of the seismic isolation unit 10c, and FIG. 4B is a cross-sectional view of FIG. 4A. In addition, in FIG. 3A and FIG. 4A, illustration of structures other than a seismic isolation unit is abbreviate | omitted.

  As shown in FIG. 1, FIG. 2A, and FIG. 2B, in this embodiment, the floor of a building is provided with each region of a seismic isolation part R1, a buffer part R2, and a border part R3.

  The seismic isolation part R1 is an area to which the floor seismic isolation system is applied, and has a function of suppressing vibration (seismic isolation function) against shaking such as an earthquake (horizontal vibration). In the present embodiment, the seismic isolation portion R1 is a square region having a side of 9 m. In the seismic isolation part R1, the girder 3 is installed on the structural floor 1, which is the floor of the building itself, via the seismic isolation device 10, and the girder 4 is arranged perpendicular to the girder 3 so that the girder 3 and the girder 3 are smaller. A seismic isolation floor 2 is formed on a frame constituted by the beams 4 via a stand 5. The seismic isolation floor 2 is formed by arranging a plurality of floor panels side by side. Thus, in the seismic isolation part R1, it is a floor seismic isolation system of a double floor structure of the structural floor 1 and the seismic isolation floor 2.

  The buffer part R2 is an area of a clearance (clearance) between the base isolation part R1 and the border part R3. In the buffer part R2, the base isolation floor 2 of the base isolation part R1 is displaced in the horizontal direction during an earthquake. This is provided to prevent a collision with the floor (fixed floor 8 described later) of the border R3. As shown in FIG. 2B, a buffer member 6 that closes the clearance between the seismic isolation portion R1 and the border portion R3 is disposed in the buffer portion R2.

  The border part R3 is an area outside (on the wall side) than the buffer part R2, and a fixed floor 8 is provided. The fixed floor 8 is disposed on the structure floor 1 via a stand 7. The fixed floor 8 is also formed by arranging a plurality of floor panels side by side in the same manner as the seismic isolation floor 2.

<Seismic isolation device>
The seismic isolation device 10 of this embodiment has three types of seismic isolation units. Specifically, as shown in FIG. 1, the seismic isolation device 10 includes a seismic isolation unit 10a, a seismic isolation unit 10b, and a seismic isolation unit 10c.

  Each of these seismic isolation units has a sliding bearing type seismic isolation bearing section (hereinafter also referred to as a common section). However, the member added to the common part is different for each seismic isolation unit.

  First, the configuration of the common unit will be described.

  Each seismic isolation unit of the present embodiment includes a sliding plate 12, a plate 13, and a support body 14 as a common part. In addition, this common part (the sliding plate 12, the plate 13, and the support body 14) is equivalent to a support part.

  The sliding plate 12 is a square plate member made of stainless steel fixed on the structural floor 1, and is arranged at the installation locations (9 locations in FIG. 1) of the seismic isolation device 10, respectively.

  The plate 13 is provided on the sliding plate 12 and can be moved relative to the sliding plate 12 in the horizontal direction (sliding). A sliding friction material is provided on the lower surface of the plate 13. In this embodiment, the friction coefficient between the sliding plate 12 and the plate 13 is made smaller than the normal friction coefficient (μ = 0.06). Specifically, the friction coefficient between the sliding plate 12 and the plate 13 is set to μ = 0.04 to 0.05. This is because it is considered that a damping force by the oil damper 100 described later is added in addition to the frictional force due to the sliding support of the seismic isolation device 10.

  The support 14 is fixed between the plate 13 and the large beam 3, and supports the seismic isolation floor 2 via the large beam 3 and the stand 5.

<About the seismic isolation unit 10a>
The seismic isolation unit 10a is provided at the midpoint portion (four locations) of each side of the square seismic isolation portion R1. Moreover, as shown to FIG. 3A, each seismic isolation unit 10a has the four coil springs 110, respectively. These four coil springs 110 are provided radially around the support 14 at intervals of 90 degrees. One end of the coil spring 110 is attached to the attachment member 20 fixed on the structure floor 1, and the other end of the coil spring 110 is attached to the protrusion of the plate 13. In other words, one end of the coil spring 110 is fixed to the structural floor 1, and the other end of the coil spring 110 is fixed to the seismic isolation floor 2 via the support 14, the large beam 3, and the stand 5. These four coil springs 110 return the positions of the structural floor 1 and the seismic isolation floor 2 to their original state (neutral position) when the structural floor 1 and the base isolation floor 2 are relatively displaced in the horizontal direction. The positional relationship between the floor 1 and the seismic isolation floor 2 is restored.

<About the operation of the seismic isolation unit 10a>
Each seismic isolation unit of the seismic isolation device 10 of this embodiment is of a sliding bearing type. That is, when the horizontal displacement occurs in the structural floor 1, the plate 13 slides (slids) on the sliding plate 12 in the horizontal direction. Thereby, the response displacement and response acceleration of the seismic isolation floor 2 with respect to the structure floor 1 can be reduced, and the shaking caused by the earthquake can be suppressed.

  Further, in the seismic isolation unit 10a, the original positional relationship can be restored even when the structural floor 1 and the seismic isolation floor 2 are relatively displaced in the horizontal direction by the restoring function of the four coil springs 110 provided radially.

  By the way, in a long-period earthquake, since it vibrates (displaces) slowly with a large width, the amount of deformation tends to increase. In order to prevent a collision between the seismic isolation floor 2 and the fixed floor 8, the area of the buffer part R <b> 2 may be increased. In that case, the area of the seismic isolation part R <b> 1 becomes smaller and the effective floor area becomes smaller. Therefore, in this embodiment, instead of the coil spring 110, by providing a base isolation unit (base isolation unit 10b, base isolation unit 10c) using a damping member (oil damper 100) that attenuates vibration, The vibration is damped. If a damping force is added even when the displacement is small, the performance of suppressing the response acceleration of the seismic isolation device 10 is degraded. Therefore, an extra damping force is not applied when the displacement is small. By doing so, the performance of suppressing the response acceleration of the seismic isolation device 10 is not deteriorated (described later).

<About the seismic isolation unit 10b>
The seismic isolation units 10b are provided at four corners of the seismic isolation part R1. That is, two pairs are provided on the diagonal line of the seismic isolation portion R1 so as to form a pair.

  2A and 2B, the seismic isolation unit 10b includes a coil spring 110 and an oil damper 100 as a configuration other than the common portion.

  Two coil springs 110 are provided for each seismic isolation unit 10b. The two coil springs 110 are provided so as to sandwich the support body 14 in a direction that is approximate to a direction orthogonal to the diagonal line of the seismic isolation portion R1 and is swung by 45 degrees with respect to the mounting direction of the large beam 3. In addition, since the installation method of the coil spring 110 is the same as that of the seismic isolation unit 10a, description is abbreviate | omitted.

  The oil damper 100 is provided on the diagonal line of the seismic isolation portion R1 so as to be orthogonal to the straight line formed by the two coil springs 110. The oil damper 100 is provided only inside the seismic isolation portion R1. That is, the oil damper 100 is provided in the position which each opposes in the two seismic isolation units 10b on the diagonal of the seismic isolation part R1.

  One end of the oil damper 100 (a connection portion 102a described later) is attached to an attachment member 21 fixed on the structure floor 1, and the other end (a connection portion 103a described later) of the oil damper 100 is connected to the support body 14. The seismic isolation floor 2 is fixed through the girder 3 and the stand 5. In other words, one end of the oil damper 100 is fixed to the structural floor 1, and the other end of the oil damper 100 is fixed to the seismic isolation floor 2 through the support body 14, the large beam 3, and the stand 5. .

  The oil damper 100 generates a damping force to attenuate the vibration when the structural floor 1 and the seismic isolation floor 2 are relatively displaced in the horizontal direction due to an earthquake or the like. In the present embodiment, since the oil damper 100 is disposed on the diagonal line in the corner portion of the seismic isolation portion R1, the damping force is effectively added to the horizontal vibration as will be described later. can do.

<About seismic isolation unit 10c>
One seismic isolation unit 10c is provided in the central part of the seismic isolation part R1. As shown in FIG. 4A, each seismic isolation unit 10c has four oil dampers 100, respectively. These four oil dampers 100 are provided around the support 14 at intervals of 90 degrees. In addition, about the installation method of the oil damper 100, since it is the same as that of the oil damper 100 of the seismic isolation unit 10b, description is abbreviate | omitted.

<About the structure of the oil damper 100>
FIG. 5 is a cross-sectional view showing a configuration of the oil damper 100 according to the present embodiment. FIG. 6 is a schematic view of the XX cross section of FIG. In FIG. 6, for convenience, the illustration of the configuration in the cylinder 102 is omitted.
The oil damper 100 of this embodiment includes a cylinder 102, a cover 103, and a piston 104. The oil damper 100 contains oil that is a viscous fluid.

  The cylinder 102 is a cylindrical member having a hollow portion, and a connecting portion 102a is provided at one end in the axial direction. The hollow portion is a portion that stores oil, and is divided into a first oil storage portion 105 and a second oil storage portion 106 by a piston 104. Further, a through hole 102b through which a piston rod 107 described later passes is provided at the other end of the cylinder 102 in the axial direction.

  The cover 103 is formed so as to cover the cylinder 102 from the other end side in the axial direction, and a connecting portion 113a is provided at the other end in the axial direction. A piston 104 is attached to the inside of the cover 103 via a piston rod 107. The piston rod 107 passes through the through hole 102 b of the cylinder 102, and the cylinder 102 is movable in the axial direction along the piston rod 107.

  The piston 104 is disposed in the hollow portion of the cylinder 102 and divides the hollow portion of the cylinder 102 into a first oil storage portion 105 and a second oil storage portion 106. The piston 104 is formed with a flow path 104a and a flow path 104b along the axial direction. And the 1st oil accommodating part 105 and the 2nd oil accommodating part 106 are connecting via these flow paths 104a and 104b.

  The flow path 104a has a one-way valve (also called a check valve) 31 so that oil can flow only in one of the axial directions. More specifically, the one-way valve 31 prohibits oil from flowing from the other end side in the axial direction (on the first oil storage unit 105 side) to one end side (on the second oil storage unit 106 side), and from one end side. Allow oil to flow to the other end. The diameter (in other words, the cross-sectional area) of the flow path 104a is so large that the oil hardly receives resistance when the oil passes through the flow path 104a.

  The flow path 114b includes a valve 32 capable of adjusting the flow rate, and can flow oil in any direction from the other end side in the axial direction to one end side and from one end side to the other end side. However, the channel 104b of the present embodiment has a smaller diameter than the channel 104a, and oil is less likely to flow (resistance is greater) than the channel 104a.

  As shown in FIGS. 5 and 6, a plurality of grooves 108 are formed in the cylinder 102 between the outer periphery of the piston 104. As shown in FIG. 5, the groove 108 is not formed in a portion on the other end side in the axial direction. Therefore, in the state of FIG. 5, the first oil storage portion 105 and the second oil storage portion 106 communicate with each other via the groove 108, but when the piston 104 moves to the left side of the figure (the left end of the piston 104 When the end of the groove 108 is reached), the flow path between the first oil storage portion 105 and the second oil storage portion 106 by the groove 108 is blocked. Note that when the oil passes through the groove 108, the oil receives almost no resistance (no damping force is generated).

<Operation of oil damper 100>
7A to 7G are diagrams for explaining the operation of the oil damper 100 of the present embodiment. In each figure, the left figure is a conceptual diagram showing the inside of the oil damper 100, and the right figure is a figure showing the relationship between displacement and stress. In the figure on the right side, the horizontal axis indicates displacement (distance between the connecting portion 102a and the connecting portion 103a), and the vertical axis indicates the generated damping force.

  First, in FIG. 7A, it is located at the neutral position, and from this state, the connecting portion 102a of the cylinder 102 is pulled in the extending direction (the direction in which the distance between the connecting portion 102a and the connecting portion 103a becomes longer). Thereby, since the relative position of the piston 104 with respect to the cylinder 102 is shifted to the left, the capacity of the first oil storage part 105 is decreased and the capacity of the second oil storage part 106 is increased. That is, the oil moves from the first oil storage part 105 to the second oil storage part 106 in the cylinder 102. At this time, the one-way valve 31 prohibits oil from flowing from the first oil accommodating portion 105 to the second oil accommodating portion 106, and therefore no oil flows through the flow path 104a. Therefore, the oil moves from the first oil storage part 105 to the second oil storage part 106 through the flow path 104b and the groove 108. At this time, the resistance received by the oil by passing through the groove 108 is small. That is, the damping force generated by the oil damper 100 is small.

  If the amount of movement (displacement) from the neutral position continues to be 200 mm as it is, the left end of the piston 104 reaches the left end of the groove 108 as shown in FIG. 7B, and the flow path passing through the groove 108 is blocked. Thereafter, the oil moves from the first oil storage portion 105 to the second oil storage portion 106 only through the flow path 104b. As described above, since it is difficult for oil to flow through the flow path 104b (resistance is large), the damping force rapidly increases as shown in FIG. 7C.

  After that, when it continues to be pulled in the extending direction, it expands while maintaining a large damping force, and eventually the elongation (displacement) becomes maximum (FIG. 7D).

  Next, the oil damper 100 is pressed in the compression direction (the direction in which the distance between the connection portion 102a and the connection portion 103a is shortened). By this pressing, the relative position of the piston 104 with respect to the cylinder 102 is shifted to the right, so that the capacity of the first oil storage part 105 increases and the capacity of the second oil storage part 106 decreases. That is, the oil moves from the second oil storage portion 106 to the first oil storage portion 105 in the cylinder 102. At this time, the one-way valve 31 permits the oil to flow from the second oil accommodating portion 106 to the first oil accommodating portion 105, so that the oil also flows to the flow path 104a. Therefore, the oil moves from the second oil storage part 106 to the first oil storage part 105 through the flow path 104a and the flow path 104b. In this case, the resistance received by the oil is small because it passes through the flow path 104a, and the damping force generated by the oil damper 100 is small.

  If the pressing is continued as it is, the position of the left end of the groove 108 overlaps with the first oil accommodating portion 105 as shown in FIG. 7F. Therefore, the oil moves through the groove 108 in addition to the flow path 104a and the flow path 104b. Even in this case, the damping force is small.

And the length (distance between the connection part 102a and the connection part 103a) of the oil damper 100 becomes the minimum, maintaining the small damping force (FIG. 7G).
Thereafter, when the oil damper 100 is extended (pulled) again, the oil passes through the flow path 104b and the groove 108 from the first oil storage portion 105 to the second oil storage portion 106, as in FIGS. 7A to 7B. Move to. Even in this case, the damping force is small. And it returns to the neutral position of FIG. 7A.

  As described above, the oil damper 100 has a large damping force that is generated only when a force is applied in the extending direction and the displacement exceeds a predetermined value, and the damping force that is generated otherwise is very small. That is, the oil damper 100 generates a two-stage damping force according to the displacement when the displacement occurs in the extension direction.

  FIG. 8A to FIG. 8C are explanatory diagrams about the damping operation of the oil damper 100 in the seismic isolation unit 10c. 8A is a diagram at the neutral position, FIG. 8B is a diagram at the time of small deformation (when the displacement is 200 mm or less), and FIG. 8C is a diagram at the time of large deformation (when the displacement exceeds 200 mm). .

  First, the structural floor 1 is displaced from the neutral position in FIG. 8A to the left side of the figure. In the small deformation of FIG. 8B, the damping force generated by the pair of oil dampers 100 is small. Therefore, the seismic isolation floor 2 is displaced mainly based on the sliding friction between the sliding plate 12 and the plate 13.

  When the displacement increases as shown in FIG. 8C, the oil damper 100 on the extending side (the right side in the figure) generates a large damping force. This damping force makes it difficult for the plate 13 (support 14) to move in the displacement direction of the structural floor 1. Therefore, the displacement of the seismic isolation floor 2 can be suppressed.

  When the structural floor 1 is displaced in the reverse direction (right side in the figure), the oil damper 100 on the left side in the figure is extended. For this reason, if the displacement of the structure floor 1 becomes large in this case, the said oil damper 100 will generate | occur | produce a big damping force, and the displacement of the seismic isolation floor 2 can be suppressed.

  By adding the oil damper 100 to the seismic isolation device 10 (the seismic isolation units 10b, 10c) in this way, almost no damping force is generated when the displacement is 200 mm or less, and large damping force is generated when the displacement exceeds 200 mm. It can generate and suppress displacement. Note that, as in the present embodiment, two (a pair) seismic isolation units 10b are arranged on the diagonal line of the seismic isolation portion R1, and oil dampers are arranged so as to face each other (to generate a damping force in opposite directions). By arranging 100, vibration can be damped efficiently. That is, in the oil damper 100 of the two (a pair) seismic isolation units 10b arranged on the diagonal line of the seismic isolation portion R1 in FIG. 1, when one contracts, the other expands. In this case, vibration can be attenuated by the oil damper 100 on the other side that extends. Conversely, when the other contracts, one expands. In this case, vibration can be attenuated by the oil damper 100 on the other side that extends.

  As described above, the oil damper 100 according to the present embodiment includes the connecting portion 102a connected to the structural floor 1, the connecting portion 103a connected to the seismic isolation floor 2, and the first oil whose capacity decreases as it expands. When the storage portion 105, the second oil storage portion 106 whose capacity increases as it expands, and the structural floor 1 and the seismic isolation floor 2 are relatively displaced, the first oil storage portion 105 and the second oil storage portion 106 And oil that can move between them.

  When the structural floor 1 and the base isolation floor 2 are relatively displaced due to an earthquake or the like and the oil damper 100 is extended, the damping force generated at a displacement larger than 200 mm is larger than the damping force generated at a displacement of 200 mm or less. I try to get bigger.

  Thereby, when the displacement is small, it is possible not to add an excessive damping force, and it is possible to suppress the response acceleration. Further, when the displacement is large, a large damping force can be applied to prevent deformation. In this way, it is possible to efficiently apply a damping force to the structural floor 1 and the seismic isolation floor 2 that are relatively displaced.

=== About Other Embodiments ===
The above embodiment is for facilitating the understanding of the present invention, and is not intended to limit the present invention. The present invention can be changed and improved without departing from the gist thereof, and it is needless to say that the present invention includes equivalents thereof. In particular, the embodiments described below are also included in the present invention.

<About the floor structure>
In the above-described embodiment, the fixed floor 8 is provided in the border portion R3. However, the present invention is not limited to this. For example, the border portion R3 may be a wall.

<About the seismic isolation device 10>
Although the seismic isolation apparatus 10 of the above-mentioned embodiment was a sliding support type, it is not restricted to this. For example, rolling bearings or laminated rubber may be used.

<About the seismic isolation unit 10b>
In the above-described embodiment, in the seismic isolation unit 10b at the corner of the seismic isolation portion R1, the oil damper 100 is provided only in the inner portion of the seismic isolation portion R1, but this is not a limitation, and the seismic isolation portion R1 You may make it provide also in an outer part. That is, two oil dampers 100 may be provided for each seismic isolation unit 10b. However, if the oil dampers 100 are arranged so as to face diagonally as in the present embodiment, the number of oil dampers 100 used can be reduced, and a damping force can be efficiently generated (attenuating vibration). )be able to.

<About sliding plate 12>
In the above-described embodiment, the shape of the sliding plate 12 is a square, but is not limited thereto. For example, it may be polygonal or circular.

<About the oil damper 100>
The piston 104 of the oil damper 100 is provided with the flow paths 104a and 104b, but the number of each flow path may be one or more. In the case of a plurality, the total cross-sectional area (resistance) of the flow path 104b only needs to be larger than the total cross-sectional area (resistance) of the flow path 104a.

  In the above-described embodiment, a plurality of grooves 108 are formed on the inner surface of the cylinder 102. However, the number of grooves 108 formed on the cylinder 102 is not limited.

  Further, in the above-described damping operation of the oil damper 100, the boundary between the small deformation and the large deformation is set to 200 mm, but the displacement can be arbitrarily set.

DESCRIPTION OF SYMBOLS 1 Structure floor 2 Seismic isolation floor 3 Large beam 4 Small beam 5 Stand 6 Buffer member 7 Stand 8 Fixed floor 10 Seismic isolation device 10a, 10b, 10c Seismic isolation unit 12 Sliding plate 13 Plate 14 Support body 20 Mounting member 21 Mounting member 31 One side Valve 32 Valve 100 Oil damper 102 Cylinder 103 Cover 104 Piston 104a Flow path 104b Flow path 105 First oil storage section 106 Second oil storage section 108 Groove 110 Coil spring

Claims (6)

An oil damper that is provided between two members that are relatively displaced and attenuates vibrations of the two members,
A first connecting portion connected to one of the two members;
A second connecting portion connected to the other member of the two members;
A first oil storage portion whose capacity decreases as the distance from the first connection portion to the second connection portion increases;
A second oil storage portion communicating with the first oil storage portion, a second oil storage portion whose capacity increases as the distance from the first connection portion to the second connection portion increases;
When the two members are relatively displaced, oil that can move between the first oil storage portion and the second oil storage portion;
Have
When the two members are relatively displaced in a direction in which the first connection portion and the second connection portion are separated from each other, a damping force generated by a displacement larger than a predetermined displacement is generated by a displacement equal to or less than the predetermined displacement. Oil damper characterized by greater than force. The oil damper according to claim 1,
The damping force generated at a displacement greater than the predetermined displacement is greater than the damping force generated when the two members are relatively displaced in a direction in which the first connection portion and the second connection portion approach each other.
Oil damper characterized by that. The oil damper according to claim 1 or 2, wherein
A cylinder having a hollow portion;
A piston that is axially movable in the hollow portion of the cylinder, and that divides the hollow portion into the first oil storage portion and the second oil storage portion according to the relative displacement of the two members;
A first flow path provided in the piston, allowing movement of the oil from the first oil accommodating portion to the second oil accommodating portion, and from the second oil accommodating portion to the first oil accommodating portion; A first flow path provided with a valve that prohibits movement of the oil to
A second flow path provided in the piston and communicating the first oil storage portion and the second oil storage portion;
With
When the relative displacement between the two members is equal to or less than the predetermined displacement, the cylinder causes the first oil storage portion and the second oil storage portion to communicate with each other, and the relative displacement between the two members is greater than the predetermined displacement. Sometimes it has a notch that cuts off the first oil container and the second oil container,
Oil damper characterized by that. The oil damper according to claim 3,
An oil damper characterized in that a channel resistance of the second channel is larger than a channel resistance of the first channel and a channel resistance of the notch. An oil damper system using the oil damper according to any one of claims 1 to 4,
Two oil dampers are provided for the one member and the other member, and each oil damper generates a damping force in a direction opposite to each other. The oil damper system according to claim 5,
The one member is a structural floor;
The other member is a seismic isolation floor provided above the structural floor.
Oil damper system characterized by that.