JP5104238B2 - Isolation device - Google Patents

Description

  The present invention relates to a vibration isolator that is interposed in a vertical gap between an upper structure and a lower structure below the upper structure.

  Isolation devices have become widespread as devices that reduce the vibrations propagating from the ground to the building during an earthquake, improve the safety of the building structure, and prevent damage to people and objects inside the building. This vibration isolator is interposed between a foundation as a lower structure and a building as an upper structure, thereby reducing the vibration response of the building to ground motion input during an earthquake. In general, as the vibration isolator, a laminated rubber, a sliding bearing, or the like that supports the building so as to be relatively movable in the horizontal direction is used.

  On the other hand, in a precision production facility such as a semiconductor factory, a lot of vibration isolators that dislike fine vibration are arranged in a building, and a lot of equipment devices that generate excitation force are also arranged. For this reason, the vibration of the building during normal times is dominated by the micro-vibration response to the excitation force inside the building, and how to reduce the micro-vibration response is important.

  However, for buildings having such a vibration isolator, from the viewpoint of preventing damage to the equipment due to the earthquake, it is preferable to apply the above-mentioned vibration isolator to dampen the building. If it is applied, there is a risk that the micro-vibration due to the exciting force or wind load inside the building that is dominant during normal times may be amplified.

Therefore, in order to solve this problem, in the vibration isolator of Patent Document 1, a lead damper is installed in parallel with a sliding bearing that supports the building's own weight while allowing horizontal vibration of the building. The lead damper can be effectively plastically deformed to effectively exhibit the vibration-isolating action of the sliding bearing.On the other hand, the micro-vibration of the building itself is made non-isolated by the high rigidity of the lead damper. I try to suppress amplification.
JP 2006-153232 A

  However, as a result of intensive studies by the present applicant, the building itself is slightly vibrated due to the non-earthquake factors that are not the vibrations that are input from the ground to the building as in the case of an earthquake, that is, the vibration source or wind inside the building. Even when the building is in a non-isolated state, it has been found that it is preferable to attenuate the building with a large damping constant while maintaining the isolated state because it can effectively suppress micro-vibration.

  FIG. 1 is an explanatory diagram thereof. The horizontal axis of FIG. 1 is the frequency of the horizontal excitation force applied to the upper part of the building, and the vertical axis of FIG. 1 is the horizontal acceleration response of the upper part of the building to the excitation force. In other words, this graph shows how many times the acceleration of the building responds with a slight vibration when the excitation force is applied to the upper part of the building. The solid line in the figure is a case of non-isolation, and the dotted line in the figure is a case of attenuation with an attenuation constant of 80% under the isolation.

  As is clear from FIG. 1, the damping with an attenuation constant of 80% under vibration isolation is a flat response curve without a large peak, rather than non-isolation. It can be seen that the effect of suppressing fine vibration is high. As a reference, 80% shows a higher suppression effect in comparison with the 20% damping constant indicated by the alternate long and short dash line. Therefore, if the damping constant is increased, the suppression effect of micro vibrations can be improved. I understand.

  However, the damping constant of the damping damper used for earthquakes is normally 10 to 20%, and the above value of 80% is much larger than this. For this reason, simply applying a damper with such a large damping constant instead of the above-mentioned earthquake damping damper makes it easy for the vibration of the ground to be transmitted to the building through the large damping force of the damper, that is, There is a risk that the building will be greatly shaken integrally with the ground, and as a result, the vibration isolation function during an earthquake may be greatly impaired.

  The present invention has been made in view of such conventional problems, and is capable of effectively suppressing fine vibrations of the non-earthquake-causing upper structure itself without impairing the vibration isolation of the upper structure during an earthquake. An object is to provide an apparatus.

In order to achieve this object, the vibration isolator shown in claim 1 is:
A vibration isolator interposed in a vertical gap between an upper structure and a lower structure below the upper structure,
A support portion that supports the weight of the upper structure while allowing horizontal reciprocal relative movement between the upper structure and the lower structure;
A low damping damper for damping horizontal relative vibrations of the upper structure and the lower structure with a predetermined damping constant;
A high damping damper interposed in the vertical gap in parallel with the low damping damper and damping the relative vibration with a damping constant larger than the predetermined damping constant,
When the relative movement amount exceeds the prescribed value in each of the forward path and backward path of said relative movement, said high damping damper Ri no longer generates the damping force,
In a state of being fixed to both the upper structure and the lower structure, the high damping damper generates a damping force according to the relative movement,
When the relative movement amount exceeds the specified value, at least one of the fixation of the high damping damper to the upper structure and the fixation to the lower structure is released.
According to the first aspect of the present invention, the fine vibration of the upper structure itself that is a non-earthquake factor can be effectively suppressed without impairing the vibration isolation of the upper structure during an earthquake.

Details are as follows. In general, the amount of relative movement between the upper structure and the lower structure during an earthquake is much larger than that of microvibration caused by non-earthquake factors. On the other hand, according to the above-described high damping damper, when the relative movement amount exceeds the specified value in each of the forward and backward paths of the relative movement, no damping force is generated. Therefore, if the specified value is appropriately set based on the assumed amplitude of micro-vibration, etc., in the event of an earthquake, adjustment should be made so that the damping force of the high damping damper is not generated in the majority of the forward and return paths of the relative movement. Can do. That is, during an earthquake, the vibration of the upper structure is damped exclusively with a small damping constant of the low damping damper, and as a result, the vibration can be suppressed without impairing the vibration isolation of the upper structure.
On the other hand, in the case of micro-vibration, most of the forward and return paths of the relative movement are within the specified values, so that the high-damping damper can function effectively, that is, the micro-vibration of the upper structure with a large damping constant. Therefore, it is possible to effectively suppress micro-vibration.

Further, by using a simple method of releasing the lock, it is possible to cause the high damping damper to perform the above-described operation of “no damping force is generated when the relative movement amount exceeds a specified value”.

Invention of Claim 2 is the vibration isolator of Claim 1 , Comprising:
The high damping damper is in contact with the container attached to the attachment surface of one of the upper structure and the lower structure, the viscous material accommodated in the container, and the viscous material, A resistance plate attached to the attachment surface of the other structure,
The damping force is a shear resistance force of the viscous material generated when the resistance plate moves relative to the container,
When the relative movement amount of the relative movement reaches the specified value and the resistance plate hits a side wall of the container, at least one of the resistance plate or the container slides with respect to the mounting surface. It is characterized by.

According to the second aspect of the present invention, a high-attenuation damper can be easily configured, and the high-attenuation damper can reliably perform the above-described operation that “a damping force is not generated when the relative movement amount exceeds a specified value”. Can be done.
Further, since the damping force of the high damping damper is the shear resistance force of the viscous material generated when the resistance plate moves with respect to the container, the magnitude of the damping force is proportional to the speed of relative movement. . Therefore, it is possible to effectively prevent the upper structure from being restrained so as not to move relatively due to a large damping force when the relative movement is started or when the relative movement is turned back. The shaking state can be reliably ensured.

Invention shown in Claim 3 is a vibration-isolating device according to claim 1 or 2,
When the relative vibration amplitude is equal to or less than a predetermined value, the low damping damper does not generate a damping force.
According to the third aspect of the present invention, the vibration isolation state of the upper structure under slight vibration can be reliably ensured regardless of the type of the low damping damper.

In other words, depending on the type of low damping damper, when the relative movement is started or when the relative movement direction is turned back, a large damping force may be applied, causing the upper structure to be in a locked state where relative movement is impossible. In this case, the upper structure cannot be maintained in a vibration-isolating state under slight vibration.
In this regard, according to the above-described vibration isolator, when the amplitude amount of the relative vibration is equal to or less than a predetermined value, the low damping damper does not generate a damping force. By setting the predetermined value, it is possible to avoid the locked state of the upper structure under slight vibration. As a result, the vibration isolation state of the upper structure can be reliably ensured even under slight vibration.

Invention of Claim 4 is the vibration isolator of Claim 3 , Comprising:
The low-damping damper is connected to the upper structure and the lower structure with play that is twice as large as the predetermined value in the horizontal direction.
According to the fourth aspect of the present invention, since the low damping damper is connected to the upper structure and the lower structure with a play twice as large as the predetermined value, the amplitude is less than the predetermined value. Under the slight amount of vibration, no damping force is generated, and thus the relative movement of the upper structure is not restricted at all. Therefore, the lock state of the upper structure that may occur depending on the type of the low-damping damper described above can be avoided, and as a result, the vibration isolation state of the upper structure can be reliably ensured even under slight vibration.

The invention shown in claim 5 is the vibration isolator according to any one of claims 1 to 4 ,
The damping constant of the low damping damper is an arbitrary value in the range of 10 to 20%,
The damping constant of the high damping damper is an arbitrary value of 50% or more and less than 100%.
According to the fifth aspect of the present invention, the vibration can be effectively damped by the low damping damper during an earthquake, while the vibration can be effectively damped by the high damping damper during a slight vibration.

The invention shown in claim 6 is the vibration isolator according to any one of claims 1 to 5 ,
The specified value is an arbitrary value not including zero and not more than 1 centimeter.
According to the sixth aspect of the invention, the vibration is effectively damped by the low damping damper without functioning the high damping damper at the time of the earthquake, while the vibration is effectively damped by the high damping damper at the time of the slight vibration. can do.

The invention shown in claim 7 is a vibration isolator that is interposed in a vertical gap between an upper structure and a lower structure below the upper structure.
A support portion that supports the weight of the upper structure while allowing horizontal reciprocal relative movement between the upper structure and the lower structure;
A low damping damper for damping horizontal relative vibrations of the upper structure and the lower structure with a predetermined damping constant;
A high damping damper interposed in the vertical gap in parallel with the low damping damper and damping the relative vibration with a damping constant larger than the predetermined damping constant,
When the relative movement amount exceeds a specified value in each of the forward path and the return path of the relative movement, the high damping damper does not generate a damping force,
The support part is a laminated rubber formed by alternately laminating metal plates and rubber plates vertically,
The rubber plate is made of natural rubber,
The upper end portion of the laminated rubber is fixed to the upper structure, and the lower end portion of the laminated rubber is fixed to the lower structure, and the laminated rubber is shear elastic in the horizontal direction according to the relative movement. It is characterized by being deformed.
According to the seventh aspect of the present invention, since laminated rubber is used for the support part and natural rubber is used for the rubber plate, the horizontal rigidity of the support part is low and the shear deformation is smoothly performed in the horizontal direction. To do. Therefore, at the start of the relative movement or when the relative movement is turned back, it is possible to effectively avoid restraining the upper structure in a locked state in which the relative movement is impossible. The body's vibration isolation state can be reliably secured.

  Further, since the laminated rubber as the support portion undergoes shear elastic deformation along with the relative movement, an elastic force in the opposite direction is generated during the elastic deformation. Therefore, the relatively moved upper structure returns quickly while vibrating to a predetermined reference position in the lower structure using the elastic force as a restoring force, so that the horizontal direction between the upper structure and the lower structure is increased. A large misalignment is prevented.

  According to the vibration isolator according to the present invention, it is possible to effectively suppress fine vibration of the upper structure itself that is a non-earthquake factor without impairing the vibration isolation of the upper structure during an earthquake.

=== The vibration isolator 10 of the first embodiment ===
FIG. 2 is a conceptual diagram of the vibration isolator 10 according to the first embodiment applied to the building 1, and a part thereof is shown in a longitudinal sectional view.

  The vibration isolator 10 is interposed in a vertical gap G between the building 1 and the foundation 3 of the building 1 provided on the ground. And the vibration isolator 10 is the horizontal relative vibration of the building 1 and the foundation 3, and the support part 20 which supports the weight of the building 1 while allowing the horizontal reciprocation of the building 1 and the foundation 3 in the horizontal direction. Is damped at a predetermined damping constant, and is interposed in the vertical gap G in parallel with the low damping damper 30 so that the relative vibration is larger than the damping constant of the low damping damper 30. And a high-attenuation damper 40 that attenuates at a high frequency.

Here, the damping constant is a general index indicating the magnitude of the vibration damping capacity of the damper, that is, the damping coefficient C of the damping damper, the mass m of the building 1, and the horizontal rigidity k of the bearing portion 20. Is represented by the following formula 1.
Decay constant h = C / (2√ (m × k)) Equation 1
Hereinafter, each component of the vibration isolator 10 will be described.

<<< Supporting part 20 >>>
The support portion 20 has a so-called laminated rubber (a steel plate and a rubber plate as an example of a metal plate, which are alternately stacked and joined together) 22 and a flange portion 24, 24 at the upper and lower ends thereof. It is fixed to the building 1 and the foundation 3, respectively. As the building 1 and the foundation 3 move in the horizontal direction, the laminated rubber 22 undergoes shear elastic deformation in the horizontal direction, whereby the building 1 is subjected to horizontal vibration isolation. At the time of this vibration isolation, elastic force in the direction opposite to the deformation direction is generated in the laminated rubber 22 along with the shear elastic deformation, but the elastic force is displaced from a predetermined reference position on the foundation 3. The building 1 functions as a restoring force for returning the building 1 to the reference position, and thereby the building 1 vibrates horizontally.

  Here, it is desirable to use a natural rubber type as the laminated rubber 22. In other words, the rubber plate is preferably made of natural rubber. The reason for this is that if the natural rubber is used, the horizontal rigidity of the laminated rubber 22 can be remarkably lowered, so that the laminated rubber 22 can be applied not only to an earthquake but also to a small excitation force such as a slight vibration. As a result, the building 1 can be maintained in a vibration-isolating state without restraining the building 1 and the foundation 3 in a locked state in which the building 1 and the foundation 3 cannot be moved relative to each other even during the slight vibration. is there. Specifically, it is preferable that the laminated rubber 22 has a horizontal restoring force characteristic that is linear within a practical range, and a permeation viscosity attenuation constant obtained from a hysteresis loop is 1 to 2%.

<<< Low damping damper 30 >>>
The low damping damper 30 is a damper that functions mainly during an earthquake. Therefore, the attenuation constant is set to an arbitrary value in a low numerical range of 10 to 20% in order to effectively attenuate the vibration at the time of the earthquake, and is set to 20% here.

  As shown in FIG. 1, a so-called oil damper 30 is applied here as the low damping damper 30. The oil damper 30 includes a cylinder 32 in which oil is sealed, a piston 34 that is slidably fitted in the cylinder 32 in a horizontal direction, and that separates the cylinder 32 into two cylinder chambers 32a and 32b, and a piston 34 And an orifice 34a communicating with the two cylinder chambers 32a and 32b. The cylinder 32 and the piston 34 are connected to the building 1 and the foundation 3 via connecting members such as a clevis 36 and a connecting pin 37, respectively. Therefore, when relative vibration occurs between the building 1 and the foundation 3, the piston 34 moves relative to the cylinder 32. At this time, the cylinder chamber 32a (32b) to the other cylinder chamber 32b ( The viscous resistance force of the oil passing through the orifice 34a acts as a vibration damping force to move to 32a), and thereby the relative vibration between the building 1 and the foundation 3 is damped.

The damping constant of the low damping damper 30 is set by appropriately adjusting specifications such as orifice diameter, oil viscosity, cylinder 32 and piston 34 size, and the like.
If the attenuation constant is as low as 10 to 20%, the low attenuation damper 30 hardly inhibits the vibration isolation state of the building 1 during an earthquake.

<<< High damping damper 40 >>>
The high-damping damper 40 is a damper that functions mainly when the building 1 itself vibrates slightly due to an excitation force or wind load inside the building 1. Therefore, in order to effectively attenuate the minute vibration, the attenuation constant is set to an arbitrary value in a high numerical range of 50% or more and less than 100%, and is set to 80% here.

  However, when the damping constant is increased in this way, as described above, the vibration of the ground is easily transmitted to the building 1 through the large damping force, and as a result, the vibration isolating action of the building 1 by the support portion 20 is increased during an earthquake. It will be damaged.

  For this reason, the high damping damper 40 generates a damping force at the time of slight vibration, but generally does not generate a damping force at the time of an earthquake having a larger amplitude than the vibration. That is, a damping force is generated until the relative movement amount exceeds the predetermined specified value δ determined from the assumed amplitude amount at the time of slight vibration in each of the forward movement and the return movement of the relative movement between the building 1 and the foundation 3. When δ is exceeded, no damping force is generated.

  Specifically, the assumed amplitude amount during micro-vibration is usually several tens of microns to several hundreds of microns and at most 0.5 centimeters. Here, the relative movement amount means a one-way movement distance in the forward or return path of the relative movement, that is, the vibration amplitude amount corresponds to twice the value. Therefore, here, the prescribed value δ is set to 1 centimeter (= 0.5 centimeter × 2 times) based on the maximum value of the assumed amplitude amount at the time of microvibration.

  If set in this way, the relative movement amount based on the assumed amplitude amount at the time of an earthquake is generally several centimeters to several tens of centimeters. Therefore, at the time of the earthquake, each of the first and second return paths of the relative movement is the first. The high damping damper generates a damping force only for 1 centimeter, but the damping force disappears when it exceeds 1 centimeter. Therefore, in the event of an earthquake, the high damping damper 40 has a damping force in most of the forward and return paths of the relative movement. Will not occur. As a result, in the event of an earthquake, the high-attenuation damper 40 is not substantially functioned, and the vibration of the building 1 is attenuated exclusively by the small 20% attenuation constant of the low-attenuation damper 30, so that the isolation of the building 1 is not impaired. The vibration during an earthquake can be suppressed.

On the other hand, at the time of slight vibration, the forward and return paths of the relative movement are within the range of 1 centimeter, which is the specified value δ. As a result, a slight vibration of the building 1 is effectively suppressed with a large damping constant of 80%. Incidentally, at the time of the minute vibration, not only the high damping damper 40 but also the laminated rubber 22 and the low damping damper 30 function, but these damping constants are much smaller than the high damping damper 40, and the influence of the damping force is ignored. FIG. 3 is an explanatory diagram of a specific configuration of the high-damping damper 40 having a function of eliminating the damping force according to the above-described relative movement amount, and is shown in a vertical cross-sectional view. .

As shown in FIG. 3, a so-called viscous damper is used here as the high damping damper 40.
The viscous damper 40 is attached to the attachment surface 1a on the lower surface of the building 1 while being in contact with the container 42 attached to the attachment surface 3a on the upper surface of the foundation 3, the viscous material 43 filled in the container 42, and the viscous material 43. The resistance plate 44 is provided. The viscous material 43 is made of high viscosity oil or silicon having a kinematic viscosity of several thousand to several million centistokes. Therefore, when the resistance plate 44 is moved relative to the container 42 in the horizontal direction, a shear resistance force is generated in the viscous material 43, which becomes a damping force and attenuates the relative vibration between the building 1 and the foundation 3.

  Here, the inner method of the container 42 is set to a dimension that is larger in the horizontal direction by the specified value δ than the resistance plate 44 accommodated in the container 42, and thereby the resistance plate within the container 42. 44 is capable of relative movement in the horizontal direction by the specified value δ, but further relative movement is restricted to be impossible. The resistance plate 44 is completely fixed to the mounting surface 1a of the building 1 by bolting or the like so that it cannot move, but the container 42 is completely fixed to the mounting surface 3a of the foundation 3. That is, it is only fixed by the maximum static frictional force between the lower surface of the container 42 and the mounting surface 3a of the foundation 3. Therefore, when a horizontal force having a magnitude exceeding the maximum static frictional force acts on the container 42, the container 42 is released from being fixed to the mounting surface 3a of the foundation 3 and horizontally on the mounting surface 3a. Slip and move relative to the foundation 3.

  Therefore, as shown in FIGS. 4A to 4C, the resistance plate 44 and the container 42 move relative to each other until the relative movement amount reaches the specified value δ in the relative movement between the building 1 and the foundation 3. Based on the speed of the relative movement, the viscous material generates a damping force F. However, as shown in FIG. 4C, the relative movement amount reaches a specified value δ, and the resistance plate 44 is applied to the side wall 42b of the container 42. When the collision occurs, the container 42 and the mounting surface 3a are released from being fixed, and as shown in FIGS. 4D and 4E, the container 42 is pushed by the resistance plate 44 and slides together with the mounting surface 3a. In the remaining path (see FIGS. 4C to 4E), the damping force is lost.

  Similarly, in the return path of relative movement, as shown in FIGS. 4E to 4G, the resistance plate 44 and the container 42 move relative to each other until the relative movement amount reaches the specified value δ, and the relative movement speed increases. Accordingly, the viscous material generates a damping force F. When the relative movement amount reaches a specified value δ and the resistance plate 44 collides with the side wall 42b of the container 42 as shown in FIG. 4H and FIG. 4I, the container 42 is pushed by the resistance plate 44 and integrally slides on the attachment surface 3a, and as a result, the remaining path ( In FIGS. 4G to 4I), the damping force disappears.

  The adjustment of the magnitude of the maximum static frictional force is performed by adjusting the roughness of the attachment surface 3a and the lower surface of the container 42 in contact with the attachment surface 3a, coating treatment on these contact surfaces, and the like. The static friction force is set to a value larger than the maximum value of the assumed shear resistance force of the viscous material at the time of slight vibration. In this way, the container 42 is firmly fixed to the foundation 3 at the time of slight vibration, and the damping force is surely generated.

  The damping constant of the high damping damper 40 is set, for example, by the kinematic viscosity of the viscous material 43, the planar size of the resistance plate 44, the three-dimensional size of the container 42, or the vertical distance between the resistance plate 44 and the bottom surface of the container 42. This is done by appropriately adjusting the specifications.

  Incidentally, since the damping force generated by the viscous damper 40 is a shear resistance force of the viscous material 43 generated when the resistance plate 44 moves relative to the container 42, the magnitude of the damping force is Purely proportional to the speed of relative movement. Therefore, it is possible to effectively prevent the building 1 from being locked in a locked state in which relative movement is not possible due to a large damping force at the start of relative movement related to micro vibrations or when the relative movement is turned back. Thus, the vibration isolation state of the building 1 can be reliably maintained even under the setting of a large attenuation constant.

=== Second Embodiment and Third Embodiment ===
In the vibration isolator 10 of the first embodiment, the low damping damper 30 is connected to the building 1 and the foundation 3 without providing play in the horizontal direction. However, depending on the type of the low damping damper 30, when the relative movement is started or when the relative movement direction is turned back, a large damping force may be applied to restrain the building 1 in a locked state where relative movement is impossible. Therefore, it becomes difficult to maintain the building 1 in a vibration-isolating state under slight vibration.

  Therefore, in the second embodiment, the low damping damper 30a is connected to the building 1 and the foundation 3 with play in the horizontal direction (see FIG. 5). Other points are the same as in the first embodiment.

  The magnitude of the play is set based on the maximum value of the assumed amplitude amount at the time of slight vibration (corresponding to the “predetermined value” in the claims, hereinafter also referred to as the predetermined value). The size is set to twice the predetermined value λ. Therefore, in the slight vibration with the amplitude amount equal to or less than the predetermined value λ, the relative movement between the building 1 and the foundation 3 is not input to the low damping damper 30a due to the play, and no damping force is generated. As a result, inhibition of vibration isolation by the low-damping damper 30a under slight vibration is reliably prevented.

  FIG. 5 is an explanatory view of an example of the connecting structure having the play, and shows the low damping damper 30a in a longitudinal sectional view.

  The pair of clevises 35, 35 of the low damping damper 30a are connected to the bracket 1b of the building 1 and the bracket 3b of the foundation 3 via connecting pins 37, respectively. Specifically, with the holes h of the brackets 1b and 3b aligned with the holes 35h of the clevis 35, the connection pins 37 are inserted into the holes 35h and h in a skewered manner and connected.

  However, the connection pin 37 is inserted into the hole h of the brackets 1b and 3b without a gap as in a so-called tight fit. On the other hand, the hole 35h of the clevis 35 is interposed between the connection pin 37 and the hole h. The gap of the predetermined value λ has a long hole shape formed in the horizontal direction, whereby the connecting pin 37 and the clevis 35 are allowed to move in the horizontal direction by the predetermined value λ. Yes. And the said clearance gap is provided with respect to each of a pair of clevis 35 and 35, As a result, the low attenuation | damping damper 30a is twice as large as the said predetermined value (lambda) in the horizontal direction as mentioned above as a whole. It is connected to the building 1 and the foundation 3 with play.

  Desirably, the inner peripheral surface of the hole 35h of the clevis 35 is covered with a sheet member made of an elastic body such as rubber or a viscoelastic body over the entire circumference, and then the connecting pin 37 and the hole 35h are covered. It is possible to prevent the occurrence of a collision sound.

  Further, the gap may be provided only in one of the clevises 35 without being provided in both of the pair of clevises 35, 35. In this case, the size of the gap is 2 of the predetermined value λ. Needless to say, it is set to double the size. Further, the gap may be formed in the hole h of the brackets 1b and 3b without being formed in the hole 35h of the clevis 35.

  6A and 6B are explanatory diagrams of the third embodiment. In the third embodiment, a so-called friction damper is used for the low damping damper 30b. However, on the basis of the same concept as that of the second embodiment described above, a contrivance is made to prevent the low damping damper 30b from inhibiting the vibration isolation of the building 1 under slight vibration. That is, when the amplitude of relative vibration between the building 1 and the foundation 3 is equal to or less than the predetermined value λ, the friction damper 30b is configured not to generate a damping force.

  As shown in FIG. 6A, the friction damper 30b has a friction plate 38 such as Teflon fixed to the building 1 and a sliding plate 39 such as stainless steel fixed to the foundation 3 so as to face the friction plate 38. ing. In a state where there is no relative movement between the building 1 and the foundation 3, that is, in a state where the relative displacement amount in which the laminated rubber 22 of the support portion 20 is not shear-deformed in the horizontal direction is zero (FIG. 6A), these friction plates A gap S having a predetermined size is formed between the slide plate 38 and the slide plate 39.

  However, here, when the building 1 and the foundation 3 are moved relative to each other in the horizontal direction as shown in FIG. 6B, the total height of the laminated rubber 22 becomes lower due to the shear deformation as the relative displacement amount increases. 1 sinks downward as a whole (see solid line and two-dot chain line in FIG. 6B). Accordingly, the gap S gradually decreases as the relative displacement amount increases, and becomes zero after reaching the predetermined relative displacement amount. That is, when the relative displacement is larger than that, as shown in FIG. 6C, the friction plate 38 and the sliding plate 39 move relative to each other while sliding, and the frictional force between the friction plate 38 and the sliding plate 39 is the same. This frictional force functions as a damping force F.

  Therefore, if the size of the gap S in which the relative displacement amount is zero shown in FIG. 6A is set so that the gap S becomes zero when the relative displacement is performed by the predetermined value λ as shown in FIG. 6B, When the amplitude of relative vibration between the building 1 and the foundation 3 is less than the predetermined value λ, the friction damper 30b can be prevented from generating the damping force F. It should be noted that if an elastic body such as a rubber plate is interposed between the lower surface of the block 31 that is integrally formed so as to protrude from the lower surface of the building 1 and the friction plate 38, the friction plate 38 and the sliding plate 39 can slide. The bias is eliminated, and as a result, the frictional force can be generated more appropriately.

=== Other Embodiments ===
As mentioned above, although embodiment of this invention was described, this invention is not limited to this embodiment, The deformation | transformation as shown below is possible in the range which does not deviate from the summary.

  In the above-described embodiment, the laminated rubber is exemplified as the support portion 20 of the vibration isolator 10, but the invention is not limited to this, and a steel ball is formed between a pair of upper and lower sliding plates or a pair of upper and lower sliding plates. You may apply the rolling bearing which pinches | interposes. However, in the case of a sliding bearing or a rolling bearing, depending on the specifications, the building 1 and the foundation 3 may be restrained in a locked state where relative movement is not possible during slight vibration. Therefore, it is desirable to use a laminated rubber as the support portion 20 and a natural rubber laminated rubber.

  In the above-described embodiment, the vibration isolator 10 is interposed in the vertical gap G between the building 1 and the foundation 3, but is not limited to this. For example, when the building 1 is composed of multiple floors, the vibration isolator 10 is interposed in the vertical gap between the upper floor slab as the upper structure and the lower floor ceiling slab as the lower structure. You may do it.

  In the above-described embodiment, the viscous damper is exemplified as the high damping damper 40. However, the present invention is not limited to this, and an oil damper, a friction damper, a steel damper, or the like may be used. However, in the case of these dampers, depending on the specifications, the building 1 is restrained in a locked state in which the relative movement is impossible by applying a large damping force at the start of the relative movement related to micro vibrations or when the relative movement is turned back. Therefore, it is preferable to use a viscous damper because there is a possibility that the vibration isolation state of the building cannot be ensured at the time of slight vibration.

  In the above-described embodiment, the oil damper and the friction damper are exemplified as the low damping damper 30. However, the present invention is not limited to this, and a viscous damper or a steel damper may be applied.

  In the above-described embodiment, the resistance plate 42 of the high damping damper 40 is completely fixed to the building 1 while the container 44 is fixed to the foundation 3 by the maximum static frictional force. Anyway. That is, the resistance plate 42 may be fixed to the mounting surface 1a of the building 1 with the maximum static frictional force, while the container 44 may be completely fixed to the mounting surface 3a of the foundation 3 by bolting or the like. Further, the attachment target of the resistance plate 42 and the container 44 may be reversed. That is, the container 44 may be attached to the building 1 side and the resistance plate 42 may be attached to the foundation 3 side.

  In the above-described embodiment, 1 centimeter is illustrated as an example of the specified value δ at which the high-attenuation damper 40 starts to slide, but is not limited to this if the zero is excluded. For example, the specified value δ is set to zero. It may be set to an arbitrary value of 1 centimeter or less.

  In the above-described embodiment, the magnitude relationship between the specified value δ of the relative movement amount and the predetermined value λ of the vibration amplitude is not specified, but it is preferable to set δ = 2λ. In this case, the high damping damper 40 at the time of slight vibration is used. Thus, the transition from the function of (1) to the function of the low-damping damper 30 during an earthquake is performed more smoothly. If δ> 2λ, depending on the type of the low-damping damper, if the building 1 is locked in a locked state in which relative movement is not possible due to large damping acting on the folded characters in the relative movement direction or at the start of relative movement. The amount of amplitude at which the high damping damper acts as a slight vibration is in the range up to 2λ. When δ <2λ, the low damping damper is in the range where the relative movement exceeds δ and reaches 2λ.

  In the third embodiment described above, the friction damper 30b is exemplified as having the friction plate 38 fixed to the building 1 and the sliding plate 39 fixed to the foundation 3 so as to face the friction plate 38. Not limited to this, the sliding plate 39 fixed to the building 1 and the friction plate 38 fixed to the foundation 3 so as to face the sliding plate 39 may be provided. In this case, the block 31 protrudes from the upper surface of the foundation 3 and is integrally formed, and a friction plate 38 is installed on the upper surface of the block 31.

It is a figure which shows the relationship between the frequency of the horizontal excitation force provided to the building upper part, and the acceleration response of the horizontal direction of the building upper part with respect to the said excitation force. It is a conceptual diagram of the vibration isolator 10 of 1st Embodiment applied to the building 1. FIG. It is explanatory drawing of the specific structure of the high damping damper 40 provided with the function to lose damping force according to the amount of relative movements. 4A to 4I are diagrams illustrating a state in which the high damping damper 40 loses the damping force according to the relative movement amount. It is explanatory drawing of an example of the connection structure which connects the low attenuation | damping damper 30a which concerns on 2nd Embodiment to the building 1 and the foundation 3. 6A to 6C are explanatory diagrams of the low attenuation damper 30b according to the third embodiment.

Explanation of symbols

1 building, 1a mounting surface, 1b bracket,
3 foundation, 3a mounting surface, 3b bracket,
10 vibration isolator, 20 bearing part, 22 laminated rubber, 24 flange part,
30 Oil damper (low damping damper),
30a Oil damper (low damping damper),
30b Friction damper (low damping damper),
31 blocks, 32 cylinders,
32a cylinder chamber, 32b cylinder chamber,
34 piston, 34a orifice,
35 clevis, 35h hole, 36 clevis, 37 connecting pin,
38 friction plate, 39 sliding plate, 40 viscous damper (high damping damper),
42 container, 42b side wall, 43 viscous material, 44 resistance plate,
F damping force, G vertical gap, S gap, h hole

Claims (7)

A vibration isolator interposed in a vertical gap between an upper structure and a lower structure below the upper structure,
A support portion that supports the weight of the upper structure while allowing horizontal reciprocal relative movement between the upper structure and the lower structure;
A low damping damper for damping horizontal relative vibrations of the upper structure and the lower structure with a predetermined damping constant;
A high damping damper interposed in the vertical gap in parallel with the low damping damper and damping the relative vibration with a damping constant larger than the predetermined damping constant,
When the relative movement amount exceeds the prescribed value in each of the forward path and backward path of said relative movement, said high damping damper Ri no longer generates the damping force,
In a state of being fixed to both the upper structure and the lower structure, the high damping damper generates a damping force according to the relative movement,
When the relative movement amount exceeds the specified value, at least one of fixing of the high damping damper to the upper structure or fixing to the lower structure is released. apparatus. The vibration isolator according to claim 1 ,
The high damping damper is in contact with the container attached to the attachment surface of one of the upper structure and the lower structure, the viscous material accommodated in the container, and the viscous material, A resistance plate attached to the attachment surface of the other structure,
The damping force is a shear resistance force of the viscous material generated when the resistance plate moves relative to the container,
When the relative movement amount of the relative movement reaches the specified value and the resistance plate hits a side wall of the container, at least one of the resistance plate or the container slides with respect to the mounting surface. A vibration isolator characterized by. The vibration isolator according to claim 1 or 2 ,
When the relative vibration amplitude is equal to or less than a predetermined value, the low damping damper does not generate a damping force. A vibration isolator according to claim 3 ,
The vibration damping device, wherein the low damping damper is connected to the upper structure and the lower structure in a horizontal direction with a play that is twice as large as the predetermined value. A vibration isolator according to any one of claims 1 to 4 ,
The damping constant of the low damping damper is an arbitrary value in the range of 10 to 20%,
The damping device according to claim 1, wherein the damping constant of the high damping damper is an arbitrary value of 50% or more and less than 100%. A vibration isolator according to any one of claims 1 to 5 ,
The specified value is an arbitrary value not including zero and not more than 1 centimeter. A vibration isolator interposed in a vertical gap between an upper structure and a lower structure below the upper structure,
A support portion that supports the weight of the upper structure while allowing horizontal reciprocal relative movement between the upper structure and the lower structure;
A low damping damper for damping horizontal relative vibrations of the upper structure and the lower structure with a predetermined damping constant;
A high damping damper interposed in the vertical gap in parallel with the low damping damper and damping the relative vibration with a damping constant larger than the predetermined damping constant,
When the relative movement amount exceeds a specified value in each of the forward path and the return path of the relative movement, the high damping damper does not generate a damping force,
The support part is a laminated rubber formed by alternately laminating metal plates and rubber plates vertically,
The rubber plate is made of natural rubber,
The upper end portion of the laminated rubber is fixed to the upper structure, and the lower end portion of the laminated rubber is fixed to the lower structure, and the laminated rubber is shear elastic in the horizontal direction according to the relative movement. A vibration isolator characterized by being deformed.