JP6894769B2 - Seismic isolation damper - Google Patents

Description

The present invention relates to a seismic isolation damper.

The seismic isolation device is equipped with seismic isolation bearing devices such as ball isolators and laminated rubber that are interposed between the ground and the structure, and supports the structure so that it can move with respect to the ground. Insulate transmission to. In addition to the seismic isolation bearing device as described above, the seismic isolation device may be provided with a seismic isolation damper interposed between the ground and the structure. In this case, the vibration of the structure is exempted. The vibration of the structure is suppressed by dampening with the damping force generated by the seismic damper.

When an earthquake occurs, the smaller the damping force of the seismic isolation damper, the more difficult it is for the seismic isolation device to transmit the vibration of the ground to the building, and it is possible to secure high vibration insulation. On the other hand, the seismic isolation device suppresses the movement of the structure by the damping force generated by the seismic isolation damper for large-scale seismic motion in which the structure moves with a large amplitude with respect to the ground, and provides seismic isolation bearings. It is necessary to avoid the structure falling out of the device and the collision between the structure and the retaining wall surrounding the lower end of the structure.

Therefore, in the seismic isolation device, the damping force is not exerted as much as possible on the seismic isolation damper so as not to hinder the vibration insulation of the seismic isolation support device for vibrations of small amplitude, and for vibrations of large amplitude. It is preferable that the seismic isolation damper actively exerts a damping force.

In order to meet such demands, a seismic isolation damper equipped with a connecting device for connecting the ground and the damper body at one end has been proposed. This seismic isolation damper does not normally connect the ground and the damper body, and when the amplitude of the structure with respect to the ground increases, the damper body and the ground are connected by a lock pin to enable expansion and contraction of the damper body and attenuate. It is designed to exert its power (see, for example, Patent Document 1).

Further, the piston that divides the extension side chamber and the compression side chamber is provided with a passage that communicates the extension side chamber and the compression side chamber, and a lid that closes the passage when the piston moves more than a preset amount of movement from the neutral position with respect to the cylinder. There is also a proposal for a seismic isolation damper equipped with members. In this seismic isolation damper, the passage is not blocked by the lid member against the shaking of a small-to-medium-amplitude earthquake and exerts a low damping force, and the lid member blocks the passage against the shaking of a large-amplitude earthquake. It exhibits a high damping force (see, for example, Patent Document 2).

Japanese Unexamined Patent Publication No. 2013-87853 JP-A-2017-26095

If such a seismic isolation damper is used, the movement of the structure can be suppressed by exerting the damping force of the seismic isolation damper against a large-scale earthquake without impairing the vibration insulation of the seismic isolation bearing device. However, the structure of the seismic isolation damper becomes complicated because it is necessary to provide a complicated mechanism for fixing the damper body to the ground and a complicated mechanism for changing the damping force in the damper due to the occurrence of a large-scale earthquake. Not only that, it is heavy and costly.

Therefore, the present invention not only exerts a low damping force against the shaking of a small-to-medium-amplitude earthquake and exerts a high damping force against the shaking of a large-amplitude earthquake, but is also lightweight, simple in structure, and inexpensive. The purpose is to provide seismic isolation dampers.

To achieve the above object, seismic isolation damper of the present invention, a sheet cylinder, a piston for partitioning the expansion side chamber and the compression side chamber is slidably inserted into the cylinder, the piston while being inserted into the cylinder The rod to be connected, the working liquid having a volume smaller than the volume of the extension chamber and the compression side chamber filled in the extension chamber and the compression side chamber, respectively, and the extension chamber when the piston is arranged in a neutral position with respect to the cylinder and stands still. And a liquid level adjusting unit for equalizing the heights of the working liquids in the compression side chamber. In the seismic isolation damper configured in this way, if the stroke from the neutral position of the piston is small, the pressure rise in the compressed chamber of the extension side chamber and the compression side chamber is suppressed, and a low damping force is exhibited, and the stroke is large. Since the pressure rise in the compressed chamber of the extension side chamber and the compression side chamber is not restricted, a high damping force can be exhibited. In addition, the seismic isolation damper configured in this way is always low even if it expands or contracts if the moving distance from the neutral position of the piston is less than the set distance when an earthquake occurs again after an earthquake occurs. It exerts a damping force, and when it exceeds a set distance, it can always exert a high damping force regardless of whether it expands or contracts. Further, the seismic isolation damper configured in this way does not require maintenance work for adjusting the amount of working liquid in the extension side chamber and the compression side chamber after an earthquake occurs.

Further, the seismic isolation damper may be provided with a tank provided outside the cylinder to store the working liquid and compensate for the volume entering and exiting the cylinder of the rod. Even in the seismic isolation damper configured in this way, if the stroke in the neutral position of the piston is small, the pressure rise in the compressed chamber of the extension side chamber and the compression side chamber is suppressed and a low damping force is exhibited, and the stroke. If is large, the pressure rise in the compressed chamber of the extension side chamber and the compression side chamber is not restricted, so that a high damping force can be exhibited.

Further, MenShinyo damper piston is configured to move a distance from the neutral position to lower the generated damping force is less than a predetermined stroke range, the above predetermined stroke range to increase the generated damping force with respect to the cylinder. When the seismic isolation damper is configured in this way, the stroke amount for increasing the damping force can be determined by setting a predetermined stroke range.

Furthermore, the seismic isolation damper makes the volume of the working liquid filled in the extension side chamber and the compression side chamber more than half the volume of the extension side chamber and the compression side chamber when the piston is in the neutral position with respect to the cylinder. You may. With the seismic isolation damper configured in this way, the moving distance from the neutral position to increasing the damping force of the piston can be set to less than half the distance from the neutral position to the stroke end, so it can be used as a retaining wall for structures. Collision can be effectively prevented.

In addition, the seismic isolation damper has a liquid level adjusting unit that communicates the extension side chamber and the compression side chamber and has an adjustment valve that opens and closes the first passage and the first passage, and the adjustment valve is attached with a valve body and a valve body. It may have a spring for positioning the valve body at the valve opening position by force, and may be configured to open the valve when the pressure difference between the extension side chamber and the compression side chamber becomes less than a predetermined pressure.

Further, the seismic isolation damper has a second passage in which the liquid level adjusting portion communicates between the extension side chamber and the tank, a third passage in which the compression side chamber and the tank communicate with each other , and a first adjustment valve that opens and closes the second passage. And a second regulating valve that opens and closes the third passage, the regulating valve has a valve body and a spring that urges the valve body to position the valve body at the valve opening position, and has an extension side chamber and a compression side. The valve may be opened when the pressure difference between the chambers becomes less than a predetermined pressure.

In the seismic isolation damper, the liquid level adjusting unit communicates the extension side chamber and the compression side chamber, and the first passage, the extension side chamber, and the tank communicate with each other, or the compression side chamber and the tank communicate with each other. It has a passage and a regulating valve that opens and closes the first passage and the second passage or the third passage, and the regulating valve has a valve body and a spring that urges the valve body to position the valve body at the valve opening position. The valve may be opened when the pressure difference between the extension side chamber and the compression side chamber becomes less than a predetermined pressure.

Therefore, according to the seismic isolation damper of the present invention, not only can it exert a low damping force against the shaking of a small-to-medium-amplitude earthquake, it can exert a high damping force against the shaking of a large-amplitude earthquake, but it is also lightweight. Moreover, the structure is simple and inexpensive.

It is a side view in the state which the damper in 1st Embodiment is intervened between the structure and the ground together with the seismic isolation device. It is sectional drawing of the damper in 1st Embodiment. It is an enlarged sectional view of a control valve. It is sectional drawing of the 1st modification of the damper in 1st Embodiment. It is sectional drawing of the 2nd modification of the damper in 1st Embodiment. It is sectional drawing of the 3rd modification of the damper in 1st Embodiment. It is sectional drawing of the 4th modification of the damper in 1st Embodiment. It is sectional drawing of the damper in 2nd Embodiment. It is sectional drawing of the 1st modification of the damper in 2nd Embodiment. It is sectional drawing of the 2nd modification of the damper in 2nd Embodiment. It is sectional drawing of the 3rd modification of the damper in 2nd Embodiment.

Hereinafter, the present invention will be described based on the embodiments shown in the figure. The configurations common to the seismic isolation dampers of each embodiment described below are designated by the same reference numerals, and in order to avoid duplication of description, the seismic isolation dampers of one embodiment have been described. The detailed description of the configuration will be omitted in the description of the seismic isolation damper of the other embodiment.

<First Embodiment>
As shown in FIG. 1, the seismic isolation damper D11 according to the first embodiment is interposed between the structure S and the ground G together with the seismic isolation device M composed of laminated rubber placed horizontally and horizontally. Ru. As the seismic isolation device M, in addition to laminated rubber, a device S such as a ball isolator that can allow the structure S to move in the horizontal direction can be adopted.

Then, as shown in FIG. 2, the seismic isolation damper D11 is inserted into the cylinder 1, the piston 2 which is slidably inserted into the cylinder 1 and separates the extension side chamber R1 and the compression side chamber R2, and the cylinder 1. A rod 3 connected to the piston 2 and a hydraulic oil O as a hydraulic liquid filled in the cylinder 1 are provided.

Hereinafter, each part of the seismic isolation damper D11 will be described in detail. One end of the cylinder 1 is closed by a cap C, and an annular rod guide 4 is attached to the other end. The piston 2 is slidably inserted into the cylinder 1 and partitions the inside of the cylinder 1 into an extension side chamber R1 and a compression side chamber R2. Further, one end of the rod 3 is movably inserted into the cylinder 1 through the rod guide 4 and connected to the piston 2, and the other end protrudes outside the cylinder 1. In this example, the seismic isolation damper D11 is a so-called single rod type damper in which the rod 3 is inserted only into the extension side chamber R1, but it is also inserted into the compression side chamber R2 and both ends of the rod 3 are cylinders 1. It may be a so-called double-rod type damper that protrudes outward from both ends of the damper. The cap C is provided with a bracket B for connecting the seismic isolation damper D11 to the mounting portion Bs provided on the structure S, and the other end of the rod 3 is provided with a bracket connected to the mounting portion Bg provided on the ground G. 3a is provided.

Then, the extension side chamber R1 is filled with the hydraulic oil O having a volume smaller than the volume of the extension side chamber R1 in the state where the piston 2 is in the neutral position with respect to the cylinder 1. The neutral position of the piston 2 with respect to the cylinder 1 is set to the center of the stroke range of the piston 2 with respect to the cylinder 1, and does not necessarily coincide with the center of the cylinder 1. The other compression side chamber R2 is filled with gas together with hydraulic oil O having a volume smaller than the volume of the compression side chamber R2 in a state where the piston 2 is in a neutral position with respect to the cylinder 1. Specifically, the extension side chamber R1 is filled with hydraulic oil O having a volume of seven tenths of the volume of the extension side chamber R1 when the piston 2 is in the neutral position with respect to the cylinder 1. The remaining space of is filled with gas. Further, the hydraulic oil O having a volume of seven tenths of the volume of the compression side chamber R2 in the state where the piston 2 is in the neutral position with respect to the cylinder 1 is filled in the compression side chamber R2, and the remaining of the compression side chamber R2. The space is filled with gas. The amount of hydraulic oil O used in the extension side chamber R1 and the compression side chamber R2 may be filled with at least half the volume of the extension side chamber R1 and the compression side chamber R2, respectively.

The hydraulic liquid is the hydraulic oil O in this example, but may be another liquid such as water or an aqueous solution. Further, in this example, the gas is preferably an inert gas such as nitrogen that does not cause deterioration of the hydraulic oil O, but other gases such as the atmosphere can also be used.

Further, the piston 2 is provided with a damping passage 5 for communicating the extension side chamber R1 and the compression side chamber R2, and a damping valve 6 for giving resistance to the flow of hydraulic oil O passing through the damping passage 5. As the damping valve 6, various valves such as a pressure regulating valve, a relief valve, and a throttle can be used. Further, when a one-way damping valve 6 is used, a plurality of damping passages 5 are provided, and a part of the damping passages 5 is provided to allow only the flow of fluid from the extension side chamber R1 to the compression side chamber R2, and the rest are in opposite directions. It is sufficient to provide a device that allows only the flow of fluid. Further, the piston 2 includes, as a liquid level adjusting portion, a first passage 7 that communicates the extension side chamber R1 and the compression side chamber R2, and an adjustment valve 8 installed in the middle of the first passage 7.

As shown in FIG. 3, the adjusting valve 8 has a valve body 10 slidably inserted into a valve hole 9 having a diameter larger than that of the first passage 7 provided in the middle of the first passage 7, and a valve body 10. The valve body 10 is provided with springs 11 and 12 for positioning the valve body 10 at the valve opening position. The valve body 10 includes a body portion 10a that is in sliding contact with the inner circumference of the valve hole 9, and valve heads 10b and 10c that protrude in the axial direction from both ends of the body portion 10a in the axial direction and have an outer diameter larger than that of the first passage 7. It is provided with a valve body passage 10d that opens from the side of the valve head 10b, penetrates the body portion 10a, and opens to the side of the valve head 10c. The body portion 10a of the valve body 10 is sandwiched by springs 11 and 12 housed in the valve hole 9 from both sides in the axial direction. The springs 11 and 12 are both housed in the valve hole 9 in a compressed state, and the valve body 10 is biased by the springs 11 and 12 and positioned in a neutral position with respect to the valve hole 9. In the regulating valve 8, when the valve body 10 is in the neutral position, the valve heads 10b and 10c are separated from the left and right openings in FIG. 3 to the valve hole 9 of the first passage 7, and the first passage 7 is opened. The extension side chamber R1 and the compression side chamber R2 are maintained in a communicating state. On the other hand, the valve body 10 moves to the left in FIG. 3, and the valve head 10b abuts on the opening of the first passage 7 to the valve hole 9, or the valve body 10 moves to the right in FIG. Then, when the valve head 10c abuts the opening of the first passage 7 to the valve hole 9, the first passage 7 is closed and the communication between the extension side chamber R1 and the compression side chamber R2 is cut off through the first passage 7. Is done.

The valve body 10 receives the pressure of the extension side chamber R1 and the compression side chamber R2, is pressed to the right side in FIG. 3 by the pressure of the extension side chamber R1, and is pressed to the left side in FIG. 3 by the pressure of the compression side chamber R2. ing. When the pressure difference between the extension side chamber R1 and the compression side chamber R2 is less than a predetermined pressure, the valve body 10 does not move until the first passage 7 is closed, the adjusting valve 8 is opened, and the pressure and compression side of the extension side chamber R1. When the pressure difference in the chamber R2 becomes equal to or higher than a predetermined pressure, the valve body 10 moves to a position where the first passage 7 is closed, and the adjusting valve 8 is closed. As described above, the adjusting valve 8 is adapted to open when the pressure difference between the extension side chamber R1 and the compression side chamber R2 becomes less than a predetermined pressure, and the predetermined pressure is the spring 11 in the state where the valve body 10 is in the neutral position. , 12 is set by the initial load which is the urging force and the spring constants of the springs 11 and 12.

Further, in this example, in the installation position of the first passage 7, the piston 2 is in a neutral position with respect to the cylinder 1, and the liquid levels of the hydraulic oil O filled in the extension side chamber R1 and the compression side chamber R2 are equal. At that time, the liquid level of the hydraulic oil O is set to be located exactly in the width in the vertical direction in FIG. 2 of the first passage 7. Then, when the piston 2 returns to the neutral position with respect to the cylinder 1 and stands still after the seismic isolation damper D11 expands and contracts, the pressure difference between the extension side chamber R1 and the compression side chamber R2 decreases and the adjusting valve 8 opens. Then, even if the liquid level of the hydraulic oil O is biased between the extension side chamber R1 and the compression side chamber R2, the extension side chamber R1 and the compression side chamber R2 are in a communicating state due to the opening of the adjusting valve 8, and the extension side chamber R1 and the compression side chamber R1 The hydraulic oil O and the gas are exchanged with R2, and the liquid levels of the hydraulic oil O in the extension side chamber R1 and the compression side chamber R2 can be made equal.

The operation of the seismic isolation damper D11 configured in this way will be described. When the piston 2 moves to the left from the neutral position shown in FIG. 2 with respect to the cylinder 1, the extension side chamber R1 is compressed and the volume decreases as the piston 2 moves, and the pressure in the extension side chamber R1 rises. .. The volume of the opposite compression side chamber R2 increases as the piston 2 moves, so that the pressure is reduced. Since the pressure difference between the extension side chamber R1 and the compression side chamber R2 causes the regulating valve 8 to block the first passage 7, the hydraulic oil O and the gas move from the extension side chamber R1 to the compression side chamber R2 via the first passage 7. Is regulated. The volume decrease in the extension chamber R1 due to the movement of the piston 2 is compensated by the decrease in the volume of gas in the extension chamber R1 and the discharge of hydraulic oil O through the damping passage 5, and the volume increase in the compression side chamber R2 is compensated. It is compensated by the expansion of the volume of gas in the compression side chamber R2 and the inflow of hydraulic oil O through the damping passage 5. When the moving distance of the piston 2 from the neutral position is less than the predetermined stroke range, the pressure increase in the extension side chamber R1 is suppressed because the compression amount of the gas in the extension side chamber R1 and the expansion amount of the gas in the compression side chamber R2 are small. At the same time, the pressure decrease in the compression side chamber R2 is suppressed, and the amount of hydraulic oil passing through the damping passage 5 is small. Therefore, when the moving distance of the piston 2 from the neutral position is less than the predetermined stroke range, the pressure difference between the extension side chamber R1 and the compression side chamber R2 is small, and the seismic isolation damper D11 exhibits a low damping force.

On the other hand, when the moving distance of the piston 2 from the neutral position exceeds a predetermined stroke range, the amount of compression of the gas in the extension side chamber R1 and the amount of expansion of the gas in the compression side chamber R2 are large, and the amount of expansion of the gas in the compression side chamber R2 is large, and the extension side chamber passes through the damping passage 5. The amount of hydraulic oil that moves from R1 to the compression side chamber R2 also increases. Then, the pressure difference between the extension side chamber R1 and the compression side chamber R2 also increases according to the movement distance of the piston 2, so that the seismic isolation damper D11 exerts a high damping force according to the movement distance of the piston 2 from the neutral position. It will be demonstrated.

Further, when the piston 2 moves to the right from the neutral position shown in FIG. 2 with respect to the cylinder 1, the compression side chamber R2 is compressed and the volume decreases as the piston 2 moves, and the pressure in the compression side chamber R2 increases. To rise. The volume of the opposite extension chamber R1 increases as the piston 2 moves, so that the volume is reduced. Since a difference in pressure between the compression side chamber R2 and the extension side chamber R1 occurs and the regulating valve 8 closes the first passage 7, the hydraulic oil O and the gas move from the compression side chamber R2 to the extension side chamber R1 via the first passage 7. Is regulated. The volume decrease in the compression side chamber R2 due to the movement of the piston 2 is compensated by the decrease in the volume of the gas in the compression side chamber R2 and the discharge of the hydraulic oil O through the damping passage 5, and the volume increase in the extension chamber R1 is compensated. It is compensated by the expansion of the volume of gas in the extension side chamber R1 and the inflow of hydraulic oil O through the damping passage 5. When the moving distance of the piston 2 from the neutral position is less than the predetermined stroke range, the pressure increase in the compression side chamber R2 is suppressed because the compression amount of the gas in the compression side chamber R2 and the expansion amount of the gas in the extension side chamber R1 are small. At the same time, the pressure decrease in the extension side chamber R1 is suppressed, and the amount of hydraulic oil passing through the damping passage 5 is small. Therefore, when the moving distance of the piston 2 from the neutral position is less than the predetermined stroke range, the pressure difference between the compression side chamber R2 and the extension side chamber R1 is small, and the seismic isolation damper D11 exhibits a low damping force.

On the other hand, when the moving distance of the piston 2 from the neutral position exceeds a predetermined stroke range, the amount of compression of the gas in the compression side chamber R2 and the amount of expansion of the gas in the extension side chamber R1 are large, and the pressure side chamber passes through the damping passage 5 and passes through the compression side chamber R1. The amount of hydraulic oil that moves from R2 to the extension chamber R1 also increases. Then, the pressure difference between the compression side chamber R2 and the extension side chamber R1 increases according to the moving distance of the piston 2, so that the seismic isolation damper D11 exerts a high damping force according to the moving distance of the piston 2 from the neutral position. It will be demonstrated.

As described above, the seismic isolation damper D11 of this example is compressed among the extension side chamber R1 and the compression side chamber R2 with a stroke less than a predetermined stroke range even if the piston 2 moves from the neutral position and extends or contracts. The pressure rise of the chamber is suppressed and a low damping force is exhibited, and a stroke of a predetermined stroke range or more does not hinder the pressure rise of the compressed chambers of the extension side chamber R1 and the compression side chamber R2, so that a high damping force can be exhibited. The predetermined stroke range may be set so as to be suitable depending on the stroke limit of the structure S on which the seismic isolation damper D11 is installed with respect to the ground G. The predetermined stroke range is the ratio of the volume of the hydraulic oil O in the extension side chamber R1 to the volume of the extension side chamber R1, the adjustment of the gas pressure in the extension side chamber R1, and the volume of the hydraulic oil O in the compression side chamber R2 to the volume of the compression side chamber R2. It can be set by adjusting the ratio and the pressure of the gas in the compression side chamber R2. Further, in this example, the extension side chamber R1 and the compression side chamber R2 are filled with gas, but the seismic isolation damper D11 exhibits the same operation even if the vacuum is not filled with the gas. In the case of a vacuum, the predetermined stroke range is the adjustment of the ratio of the volume of the hydraulic oil O in the extension side chamber R1 to the volume of the extension side chamber R1 and the ratio of the volume of the hydraulic oil O in the compression side chamber R2 to the volume of the compression side chamber R2. It can be set by adjusting.

Therefore, the seismic isolation damper D11 of this example exerts a low damping force against the shaking of an earthquake of a small and medium amplitude scale in which the moving distance of the piston 2 from the neutral position is small, and has a large amplitude. It can exert a high damping force against the shaking of an earthquake. Further, since the seismic isolation damper D11 does not need to use a device having a complicated mechanism when switching between a low damping force and a high damping force according to the moving distance of the piston 2 from the neutral position, the seismic isolation damper D11 is used. Lightweight, simple in structure and inexpensive. From the above, according to the seismic isolation damper D11 of the present invention, it is possible to exert a low damping force against the shaking of a small-to-medium-amplitude earthquake, and to exert a high damping force against the shaking of a large-amplitude earthquake. The seismic isolation damper D11 is lightweight, has a simple structure, and is inexpensive.

Further, in the seismic isolation damper D11 of this example, the generated damping force is lowered when the moving distance of the piston 2 from the neutral position with respect to the cylinder 1 is less than the predetermined stroke range, and the generated damping force is lowered when the moving distance is less than the predetermined stroke range. Is designed to be high. When the seismic isolation damper D11 is configured in this way, the stroke amount for increasing the damping force can be determined by setting a predetermined stroke range.

Further, in the seismic isolation damper D11 of this example, when the piston 2 is arranged in a neutral position with respect to the cylinder 1 and stands still, the liquid level of the hydraulic oil O in the extension side chamber R1 and the compression side chamber R2 becomes equal. It has an adjustment unit. In the seismic isolation damper D11 configured in this way, when the seismic motion has subsided and the piston 2 returns to the neutral position by the seismic isolation device M and stands still, the hydraulic oil in the extension side chamber R1 and the compression side chamber R2 Even if there is a bias in the height of the liquid level of O, this is made equal. Therefore, when an earthquake occurs next time, the seismic isolation damper D11 will always have low damping even if it expands or contracts if the moving distance from the neutral position of the piston 2 is less than the set distance (predetermined stroke range). It exerts a force, and when it exceeds a set distance (predetermined stroke range), it can always exert a high damping force regardless of whether it expands or contracts. Therefore, the seismic isolation damper D11 configured in this way does not require maintenance work for adjusting the amount of hydraulic oil O in the extension side chamber R1 and the compression side chamber R2 after an earthquake occurs.

Further, in the seismic isolation damper D11 of this example, the volume of the hydraulic oil O filled in the extension side chamber R1 and the compression side chamber R2 is set to more than half the volume of the extension side chamber R1 and the compression side chamber R2, respectively. Since the moving distance of the piston 2 from the neutral position is less than half the distance from the neutral position of the piston 2 to the stroke end, the collision of the structure S with the retaining wall can be effectively prevented.

In the above-mentioned place, the extension side chamber R1 and the compression side chamber R2 are filled with the hydraulic oil O as the working liquid and directly filled with the gas, but in one modification of the first embodiment shown in FIG. Like the seismic isolation damper D12, the extension side air chamber G1 and the compression side air chamber G2 are filled with gas, respectively, and the extension side air chamber forming member 13 and the compression side air chamber forming member 14 are formed. May be provided and the liquid level adjusting unit may be abolished.

The extension side air chamber forming member 13 is an annular free piston that is slidably inserted into the cylinder 1 and the rod 3 is slidably inserted into the inner circumference, and is between the extension side air chamber forming member 13 and the rod guide 4. It forms an extensor air chamber G1 filled with gas. Further, a stopper 15 for restricting the movement of the extension side air chamber forming member 13 to the left side in FIG. 4 is mounted on the inner circumference of the cylinder 1. The extension side air chamber forming member 13 is separated from the stopper 15 when the piston 2 is arranged in a neutral position with respect to the cylinder 1, and when the piston 2 moves to the left in FIG. 4, the extension side air chamber G1 Move to the left while compressing.

The compression side air chamber forming member 14 is a disk-shaped free piston that is slidably inserted into the cylinder 1, and is filled with gas between the compression side air chamber forming member 14 and the cap C that closes one end of the cylinder 1. It forms G2. Further, a stopper 16 for restricting the movement of the compression side air chamber forming member 14 to the right side in FIG. 4 is mounted on the inner circumference of the cylinder 1. The compression side air chamber forming member 14 is separated from the stopper 16 when the piston 2 is arranged in a neutral position with respect to the cylinder 1, and compresses the compression side air chamber G2 when the piston 2 moves to the right in FIG. While doing so, move to the right.

In the seismic isolation damper D12 configured in this way, the extension side air chamber forming member 13 can move to the left until it comes into contact with the stopper 15. Then, the extension side air chamber forming member 13 does not abut on the stopper 15 until the moving distance of the piston 2 from the neutral position to the left in FIG. 4 reaches a predetermined stroke range, and when the movement distance reaches the predetermined stroke range, the extension side The air chamber forming member 13 comes into contact with the stopper 15.

Therefore, when the seismic isolation damper D12 extends and the piston 2 strokes within a predetermined stroke range from the neutral position, the extension side air chamber forming member 13 moves in the same direction according to the movement of the piston 2. The pressure in the extension side chamber R1 does not rise so much. Further, since the compression side air chamber forming member 14 moves in the same direction according to the movement of the piston 2, the pressure in the compression side chamber R2 does not decrease so much. When the piston 2 strokes from the neutral position to less than a predetermined stroke range in this way, the pressure difference between the extension side chamber R1 and the compression side chamber R2 is small, so that the damping force exerted by the seismic isolation damper D12 is low.

On the other hand, when the moving distance of the piston 2 to the left from the neutral position exceeds a predetermined stroke range, the extension side air chamber forming member 13 comes into contact with the stopper 15 and further compresses the extension side air chamber G1. You will not be able to move. Then, the hydraulic oil O in the extension side chamber R1 is compressed by the movement of the piston 2, and the pressure in the space filled with the hydraulic oil O in the extension side chamber R1 rises significantly, passes through the damping passage 5, and is compressed from the extension side chamber R1. The amount of hydraulic oil that moves to the chamber R2 also increases. Further, the compression side air chamber forming member 14 moves in the same direction according to the movement of the piston 2, but the pressure in the compression side chamber R2 also increases within the predetermined stroke range due to the volume expansion of the compression side air chamber G2. Also decreases. Therefore, when the moving distance of the piston 2 from the neutral position exceeds a predetermined stroke range, the pressure difference between the extension side chamber R1 and the compression side chamber R2 becomes large, and the seismic isolation damper D12 exerts its own extension by exerting a high damping force. Will interfere.

Further, in the seismic isolation damper D12, the compression side air chamber forming member 14 can move to the right until it comes into contact with the stopper 16. Then, the compression side air chamber forming member 14 does not abut on the stopper 16 until the moving distance of the piston 2 from the neutral position to the right in FIG. 4 reaches a predetermined stroke range, and when the movement distance reaches the predetermined stroke range, the compression side air The chamber forming member 14 comes into contact with the stopper 16.

Therefore, when the seismic isolation damper D12 contracts, if the piston 2 strokes from the neutral position within a predetermined stroke range, the compression side air chamber forming member 14 moves in the same direction according to the movement of the piston 2. The pressure in the compression side chamber R2 does not rise so much. Further, since the extension side air chamber forming member 13 moves in the same direction according to the movement of the piston 2, the pressure in the extension side chamber R1 does not decrease so much. When the piston 2 strokes from the neutral position to less than a predetermined stroke range in this way, the pressure difference between the compression side chamber R2 and the extension side chamber R1 is small, so that the damping force exerted by the seismic isolation damper D12 is low.

On the other hand, when the moving distance of the piston 2 from the neutral position to the right exceeds a predetermined stroke range, the compression side air chamber forming member 14 comes into contact with the stopper 16 and cannot move in the direction of further compressing the compression side air chamber G2. .. Then, the hydraulic oil O in the compression side chamber R2 is compressed by the movement of the piston 2, and the pressure in the space filled with the hydraulic oil O in the compression side chamber R2 rises significantly, passes through the damping passage 5, and extends from the compression side chamber R2. The amount of hydraulic oil that moves to the side chamber R1 also increases. Further, the extension side air chamber forming member 13 moves in the same direction according to the movement of the piston 2, but the pressure in the extension side chamber R1 also moves within the predetermined stroke range due to the volume expansion of the extension side air chamber G1. Less than in the case. Therefore, when the moving distance of the piston 2 from the neutral position exceeds a predetermined stroke range, the pressure difference between the compression side chamber R2 and the extension side chamber R1 becomes large, and the seismic isolation damper D12 contracts itself by exerting a high damping force. Will interfere.

Further, in this seismic isolation damper D12, a low damping force is exerted until the extension side air chamber forming member 13 abuts on the stopper 15 at the time of extension, and until the compression side air chamber forming member 14 abuts on the stopper 16 at the time of contraction. Since it exhibits a low damping force, the damping force can be switched between high and low by the stoppers 15 and 16. Therefore, a predetermined stroke range can be easily set depending on the installation positions of the stoppers 15 and 16. That is, if the extension side air chamber forming member 13 and the compression side air chamber forming member 14 are stopped, the damping force can be switched between high and low, so that the stroke amount from the neutral position of the piston 2 in which the damping force is switched can be switched. Can be easily set. The stopper 15 may be provided on the rod guide 4 or the extension side air chamber forming member 13, and the stopper 16 may be provided on the cap C or the compression side air chamber forming member 14. When the stoppers 15 and 16 are not provided, the predetermined stroke range can be set in the same manner as the seismic isolation damper D11. That is, the ratio of the volume of the extension side air chamber G1 to the volume of the extension side chamber R1 in the state where the piston 2 is in the neutral position, the adjustment of the gas pressure in the extension side air chamber G1, and the state where the piston 2 is in the neutral position. A predetermined stroke range can be set by adjusting the ratio of the volume of the compression side air chamber G2 to the volume of the compression side chamber R2 and the pressure of the gas in the compression side air chamber G2.

Further, as in the seismic isolation damper D13 shown in FIG. 5, the extension side air chamber forming member 13 forms an extension side air chamber G1 with the piston 2, and the compression side air chamber forming member 14 is formed with the piston 2. The compression side air chamber G2 may be formed between the two. In this case, if stoppers 17 and 18 projecting toward the extension side air chamber forming member 13 and the compression side air chamber forming member 14 are provided on both sides of the piston 2, the stoppers 17 and 18 are damped by the axial lengths of the stoppers 17 and 18. A predetermined stroke range for switching between high and low forces can be set. The extension side air chamber G1 and the compression side air chamber G2 are provided with elastic bodies that return the extension side air chamber forming member 13 and the compression side air chamber forming member 14 to their original positions when the piston 2 returns to the neutral position, respectively. You may. Further, like the seismic isolation damper D13, the extension side air chamber G1 is provided between the piston 2 and the extension side air chamber forming member 13, and the compression side air chamber G2 is provided between the piston 2 and the compression side air chamber forming member 14. When provided, the damping passage 5 and the damping valve 6 may be provided outside the cylinder 1 as shown in the figure.

Further, as in the seismic isolation damper D14 shown in FIG. 6, a space that functions as a part of the extension side chamber R1 and the compression side chamber R2 is formed in the rod 3 or the piston 2, and the extension side air chamber forming member is formed in each of these spaces. 19 and the compression side air chamber forming member 20 may be inserted to form the extension side air chamber G1 and the compression side air chamber G2. In this way, the extension side air chamber forming member 19, the compression side air chamber forming member 20, the extension side air chamber G1 and the compression side air chamber G2 are less affected by the stroke length of the seismic isolation damper D14, and thus seismic isolation is achieved. It becomes easy to secure the required stroke length while shortening the total length of the damper D14.

Further, as in the seismic isolation damper D15 shown in FIG. 7, the extension side air chamber forming member 21 and the compression side air chamber forming member 22 form the extension side air chamber G1 and the compression side air chamber G2 in the internal space, respectively, and also externally. It may be a container that can expand and contract the extension side air chamber G1 and the compression side air chamber G2 by the pressure acting from. The container may be made of an elastic body such as rubber or a bellows.

In the seismic isolation dampers D12, D13, D14, and D15, gas is contained in the extension side air chamber G1 and the compression side air chamber G2, and the extension side air chamber G1 and the compression side air chamber G2 are independent of each other. Therefore, when the piston 2 stands still in the neutral position without providing the liquid level adjusting portion, the hydraulic oil O is filled in the extension side chamber R1 and the compression side chamber R2 according to the set volume. Therefore, when an earthquake occurs next time, the seismic isolation dampers D12, D13, D14, and D15 contract even if they extend when the moving distance of the piston 2 from the neutral position is less than the set distance (predetermined stroke range). Even so, it always exerts a low damping force, and when it exceeds a set distance (predetermined stroke range), it can always exert a high damping force regardless of whether it expands or contracts. Therefore, the seismic isolation dampers D12, D13, D14, and D15 configured in this way do not require maintenance work for adjusting the amount of hydraulic oil O in the extension side chamber R1 and the compression side chamber R2 after an earthquake occurs.

<Second embodiment>
As shown in FIG. 8, the seismic isolation damper D21 according to the second embodiment includes a cylinder 1, a piston 2 slidably inserted into the cylinder 1 to partition the extension side chamber R1 and the compression side chamber R2, and a cylinder. The rod 3 inserted into 1 and connected to the piston 2, the outer cylinder 30 that covers the outer periphery of the cylinder 1 and forms the tank T in the annular gap between the cylinder 1, and the inside of the cylinder 1 and the tank T are filled. It is provided with a hydraulic oil O as a hydraulic liquid to be operated.

Hereinafter, each part of the seismic isolation damper D21 will be described in detail. A valve case 31 is fitted to one end of the cylinder 1, and a rod guide 4 is fitted to the other end. One end of the outer cylinder 30 is provided with a bracket 32a connected to the mounting portion Bs provided in the structure S and is closed by a cap 32, and a rod guide 4 is mounted on the inner circumference of the other end of the outer cylinder 30. .. The cylinder 1 is sandwiched by a rod guide 4 mounted on the outer cylinder 30 and a valve case 31 that abuts on the cap 32, and is accommodated and fixed in the outer cylinder 30.

The piston 2 is slidably inserted into the cylinder 1 and partitions the inside of the cylinder 1 into an extension side chamber R1 and a compression side chamber R2. Further, the rod 3 is movably inserted into the cylinder 1 through the rod guide 4 and connected to the piston 2, and the other end thereof protrudes out of the cylinder 1. In this example, the seismic isolation damper D21 is a so-called single rod type damper in which the rod 3 is inserted only into the extension side chamber R1, but it is also inserted into the compression side chamber R2 and both ends of the rod 3 are cylinders 1. It may be a so-called double-rod type damper that protrudes outward from both ends of the damper.

Then, similarly to the seismic isolation damper D11, the extension side chamber R1 is filled with the hydraulic oil O having a volume smaller than the volume of the extension side chamber R1 in the state where the piston 2 is in the neutral position with respect to the cylinder 1. .. The other compression side chamber R2 is filled with gas together with hydraulic oil O having a volume smaller than the volume of the compression side chamber R2 in a state where the piston 2 is in a neutral position with respect to the cylinder 1. With the piston 2 in the neutral position with respect to the cylinder 1, the liquid level of the hydraulic oil O in the extension side chamber R1 and the compression side chamber R2 and the liquid level of the hydraulic oil O in the tank T coincide with each other in the tank T. The hydraulic oil O and the gas are filled.

In this example, the extension side chamber R1 is filled with hydraulic oil O having a volume of seven tenths of the volume of the extension side chamber R1 when the piston 2 is in the neutral position with respect to the cylinder 1. The remaining space of R1 is filled with gas. Further, the hydraulic oil O having a volume of seven tenths of the volume of the compression side chamber R2 in the state where the piston 2 is in the neutral position with respect to the cylinder 1 is filled in the compression side chamber R2, and the remaining of the compression side chamber R2. The space is filled with gas. The amount of hydraulic oil O used in the extension side chamber R1 and the compression side chamber R2 may be filled with at least half the volume of the extension side chamber R1 and the compression side chamber R2, respectively.

Further, the piston 2 is provided with a damping passage 5 for communicating the extension side chamber R1 and the compression side chamber R2, and a damping valve 6 for giving resistance to the flow of hydraulic oil O passing through the damping passage 5. Further, the valve case 31 has a damping passage 33 that communicates the compression side chamber R2 and the tank T, a damping valve 34 that gives resistance to the flow of hydraulic oil O passing through the damping passage 33, and a tank T to the compression side chamber R2. A suction passage 35 is provided that allows only the flow of the flowing fluid. As the damping valve 34, a damping valve having various structures can be used as in the damping valve 6, and the damping valve 34 may allow only the flow of fluid from the compression side chamber R2 to the tank T.

Further, the piston 2 includes a first passage 7 that communicates the extension side chamber R1 and the compression side chamber R2, and a regulating valve 8 installed in the middle of the first passage 7. The rod guide 4 includes a second passage 36 that communicates the extension side chamber R1 and the tank T, and a regulating valve 37 installed in the middle of the second passage 36. The regulating valve 37 has the same configuration as the regulating valve 8. In this example, the liquid level adjusting portion is composed of the first passage 7, the adjusting valve 8, the second passage 36, and the adjusting valve 37, and opens when the pressure difference between the extension side chamber R1 and the tank T becomes less than a predetermined pressure. It is designed to speak.

Further, the installation position of the second passage 36 is when the piston 2 is in a neutral position with respect to the cylinder 1 and the liquid levels of the hydraulic oil O filled in the extension side chamber R1, the compression side chamber R2 and the tank T are equal. , The liquid level of the hydraulic oil O is set to be located at the width of the second passage 36 in the vertical direction in FIG. When the seismic isolation damper D21 is in a stationary state, the pressure difference between the extension side chamber R1 and the compression side chamber R2 is small and the adjusting valve 8 is opened, and the pressure difference between the extension side chamber R1 and the tank T is small and the adjustment valve 37 is opened. .. As a result, even if the liquid level of the hydraulic oil O differs between the extension side chamber R1, the compression side chamber R2, and the tank T when the piston 2 returns to the neutral position with respect to the cylinder 1 after the seismic isolation damper D21 expands and contracts. By opening the regulating valves 8 and 37, the extension side chamber R1 and the compression side chamber R2 are communicated with each other in the first passage 7, and the extension side chamber R1 and the tank T are communicated with each other by the second passage 36. And the height of the liquid level of the hydraulic oil O in the tank T can be made equal.

The operation of the seismic isolation damper D21 configured in this way will be described. When the piston 2 moves to the left from the neutral position shown in FIG. 8 with respect to the cylinder 1, the extension side chamber R1 is compressed and the volume decreases as the piston 2 moves, and the pressure in the extension side chamber R1 rises. .. Since the volume of the opposite compression side chamber R2 increases with the movement of the piston 2, the hydraulic oil O is supplied from the tank T through the suction passage 35. Since the pressure difference between the extension side chamber R1 and the compression side chamber R2 causes the regulating valve 8 to block the first passage 7, the hydraulic oil O and the gas move from the extension side chamber R1 to the compression side chamber R2 via the first passage 7. Is regulated. Further, since the pressure difference between the extension side chamber R1 and the tank T causes the adjusting valve 37 to block the second passage 36, the hydraulic oil O and the gas move from the extension side chamber R1 to the tank T via the second passage 36. Is regulated.

The decrease in volume in the extension chamber R1 due to the movement of the piston 2 is compensated by the decrease in the volume of gas in the extension chamber R1, and the increase in volume in the compression side chamber R2 is compensated by the supply of hydraulic oil O from the tank T. .. When the moving distance of the piston 2 from the neutral position is less than the predetermined stroke range, the pressure increase in the extension side chamber R1 is suppressed because the amount of compression of the gas in the extension side chamber R1 is small, and the inside of the compression side chamber R2 is abbreviated as tank T. Since it becomes a pressure and the pressure decrease is small, the amount of hydraulic oil passing through the damping passage 5 is also small. Therefore, when the moving distance of the piston 2 from the neutral position is less than the predetermined stroke range, the pressure difference between the extension side chamber R1 and the compression side chamber R2 is small, and the seismic isolation damper D21 exhibits a low damping force.

On the other hand, when the moving distance of the piston 2 from the neutral position exceeds a predetermined stroke range, the amount of compression of the gas in the extension side chamber R1 is large, and the hydraulic oil moves from the extension side chamber R1 to the compression side chamber R2 through the damping passage 5. The amount will also increase. Then, the pressure difference between the extension side chamber R1 and the compression side chamber R2 also increases according to the movement distance of the piston 2, so that the seismic isolation damper D21 exerts a high damping force according to the movement distance from the neutral position of the piston 2. It will be demonstrated.

Further, when the piston 2 moves to the right from the neutral position shown in FIG. 2 with respect to the cylinder 1, the compression side chamber R2 is compressed and the volume decreases as the piston 2 moves, and the pressure in the compression side chamber R2 increases. To rise. The volume of the opposite extension chamber R1 increases as the piston 2 moves, so that the volume is reduced. Since a difference in pressure between the compression side chamber R2 and the extension side chamber R1 occurs and the regulating valve 8 closes the first passage 7, the hydraulic oil O and the gas move from the compression side chamber R2 to the extension side chamber R1 via the first passage 7. Is regulated. Further, since the pressure difference between the extension side chamber R1 and the tank T causes the adjusting valve 37 to block the second passage 36, the hydraulic oil O and the gas move from the tank T to the extension side chamber R1 via the second passage 36. Is regulated.

The volume decrease in the compression side chamber R2 due to the movement of the piston 2 is compensated by the decrease in the volume of the gas in the compression side chamber R2 and the discharge of the hydraulic oil O through the damping passages 5 and 33, and the volume increase in the extension chamber R1. Is compensated by the inflow of hydraulic oil O through the damping passage 5 and the expansion of the volume of gas in the extension chamber R1. When the moving distance of the piston 2 from the neutral position is less than the predetermined stroke range, the pressure increase in the compression side chamber R2 is suppressed because the compression amount of the gas in the compression side chamber R2 and the expansion amount of the gas in the extension side chamber R1 are small. At the same time, the pressure decrease in the extension side chamber R1 is suppressed, and the amount of hydraulic oil passing through the damping passages 5 and 33 is also small. Therefore, when the moving distance of the piston 2 from the neutral position is less than the predetermined stroke range, the pressure difference between the compression side chamber R2 and the extension side chamber R1 is small, so that the seismic isolation damper D21 exhibits a low damping force.

On the other hand, when the moving distance of the piston 2 from the neutral position exceeds a predetermined stroke range, the amount of compression of the gas in the compression side chamber R2 and the amount of expansion of the gas in the extension side chamber R1 are large and pass through the damping passages 5 and 33. The amount of hydraulic oil that moves from the compression side chamber R2 to the extension side chamber R1 and the tank T also increases. Then, since the pressure in the cylinder 1 increases according to the moving distance of the piston 2, the seismic isolation damper D21 exerts a high damping force according to the moving distance from the neutral position of the piston 2. ..

As described above, the seismic isolation damper D21 in the second embodiment exerts a low damping force in a stroke less than a predetermined stroke range even if the piston 2 moves from the neutral position and extends or contracts, and is predetermined. A high damping force can be exhibited with a stroke beyond the stroke range. The predetermined stroke range may be set so as to be suitable according to the stroke limit of the structure S on which the seismic isolation damper D21 is installed with respect to the ground G. The predetermined stroke range is the ratio of the volume of the hydraulic oil O in the extension side chamber R1 to the volume of the extension side chamber R1, the adjustment of the gas pressure in the extension side chamber R1, and the volume of the hydraulic oil O in the compression side chamber R2 to the volume of the compression side chamber R2. It can be set by adjusting the ratio and the pressure of the gas in the compression side chamber R2. Further, in this example, the extension side chamber R1 and the compression side chamber R2 are filled with gas, but the seismic isolation damper D11 exhibits the same operation even if the vacuum is not filled with the gas. In the case of a vacuum, the predetermined stroke range is the adjustment of the ratio of the volume of the hydraulic oil O in the extension side chamber R1 to the volume of the extension side chamber R1 and the ratio of the volume of the hydraulic oil O in the compression side chamber R2 to the volume of the compression side chamber R2. It can be set by adjusting.

Therefore, the seismic isolation damper D21 of this example exerts a low damping force against the shaking of an earthquake of a small and medium amplitude scale in which the moving distance of the piston 2 from the neutral position is small, and has a large amplitude. It can exert a high damping force against the shaking of an earthquake. Further, since the seismic isolation damper D21 does not need to use a device having a complicated mechanism when switching between a low damping force and a high damping force depending on the moving distance of the piston 2 from the neutral position, the seismic isolation damper D21 is used. Lightweight, simple in structure and inexpensive. From the above, according to the seismic isolation damper D21 of the present invention, it is possible to exert a low damping force against the shaking of a small-to-medium-amplitude earthquake, and to exert a high damping force against the shaking of a large-amplitude earthquake. The seismic isolation damper D21 is lightweight, has a simple structure, and is inexpensive.

Further, in the seismic isolation damper D21 of this example, the generated damping force is lowered when the moving distance of the piston 2 from the neutral position with respect to the cylinder 1 is less than the predetermined stroke range, and the generated damping force is lowered when the moving distance is less than the predetermined stroke range. Is designed to be high. When the seismic isolation damper D21 is configured in this way, the stroke amount for increasing the damping force can be determined by setting a predetermined stroke range.

Further, also in the seismic isolation damper D21 of this example, the volume of the hydraulic oil O filled in the extension side chamber R1 and the compression side chamber R2, respectively, may be more than half the volume of the extension side chamber R1 and the compression side chamber R2. By configuring the seismic isolation damper D21 of this example in this way, the piston 2 can exert a high damping force with a stroke of less than half the distance from the neutral position to the stroke end, and the structure S is retained. It can effectively prevent collision with the wall.

Further, in the seismic isolation damper D21 of this example, when the piston 2 is arranged in a neutral position with respect to the cylinder 1 and stands still, the adjusting valve 8 and the adjusting valve 37 open, so that the extension side chamber R1, the compression side chamber R2 and The tank T is in a communicating state by the first passage 7 and the second passage 36. In the seismic isolation damper D21 configured in this way, when the seismic motion has subsided and the piston 2 returns to the neutral position by the seismic isolation device M and stands still, the hydraulic oil in the extension side chamber R1 and the compression side chamber R2 Even if there is a bias in the height of the liquid level of O, this is made equal. Therefore, when an earthquake occurs next time, the seismic isolation damper D21 will always have low damping even if it expands or contracts if the moving distance from the neutral position of the piston 2 is less than the set distance (predetermined stroke range). It exerts a force, and when it exceeds a set distance (predetermined stroke range), it can always exert a high damping force regardless of whether it expands or contracts. Therefore, the seismic isolation damper D21 configured in this way does not require maintenance work for adjusting the amount of hydraulic oil O in the extension side chamber R1 and the compression side chamber R2 after an earthquake occurs.

As in the seismic isolation damper D22 of the modified example of the second embodiment shown in FIG. 9, instead of installing the second passage 36, the compression side chamber R2 and the tank T are provided with respect to the valve case 31. A third passage 38 that communicates with the third passage 38 and a regulating valve 39 installed in the middle of the third passage 38 may be provided. In the liquid level adjusting unit, when the piston 2 is arranged in a neutral position with respect to the cylinder 1 and stands still, the extension side chamber R1, the compression side chamber R2 and the tank T may be in a communicative state. It may be composed of all or any two passages of 36 and the third passage 38, and a regulating valve provided in each passage.

Further, as in the seismic isolation damper D23 of one modification of the second embodiment shown in FIG. 10, the extension side chamber R1 and the tank T are communicated with each other by a damping passage 40 provided with a damping valve 41 in the middle, and a piston is used. No. 2 may be provided with a rectifying passage 42 that allows only the flow of fluid from the compression side chamber R2 to the extension side chamber R1. In this case, the seismic isolation damper D23 is set to a uniflow type damper in which hydraulic oil O is discharged from the cylinder 1 to the tank T through the damping passage 40 when expanding and contracting. Even with this configuration, the seismic isolation damper D23, like the seismic isolation damper D21, has low damping when the stroke is less than the predetermined stroke range even if the piston 2 moves from the neutral position and extends or contracts. It exerts a force and can exert a high damping force in a stroke exceeding a predetermined stroke range.

Further, with respect to the seismic isolation dampers D21, D22, and D23 of the second embodiment, the extension side air chamber forming member and the compression side air chamber forming member are used as free pistons like the seismic isolation dampers D12 and D13. A structure can be adopted in which the extension side air chamber G1 is formed in the extension side chamber R1 and the compression side air chamber G2 is formed in the compression side chamber R2. In this case, like the seismic isolation damper D24 shown in FIG. 11, the extension side air chamber forming member 50 and the compression side air chamber forming member 51 slidably inserted into the cylinder 1 are provided to provide the extension side air chamber G3. And the compression side air chamber G4 may be formed.

Specifically, the extension side air chamber forming member 50 is an annular free piston that is slidably inserted into the cylinder 1 and the rod 3 is slidably inserted into the inner circumference of the rod guide 4. An extension side air chamber G3 filled with gas is formed between the two. In the extension side air chamber G3, a spring member 52 interposed between the rod guide 4 and the extension side air chamber forming member 50 is housed. Further, the extension side air chamber G3 communicates with a space filled with gas above the liquid level of the hydraulic oil O in the tank T.

The compression side air chamber forming member 51 is an annular free piston that is slidably inserted into the cylinder 1 and a columnar guide shaft 31a provided in the valve case 31 is slidably inserted into the inner circumference thereof. A pressure side air chamber G4 filled with gas is formed between the cylinder and the valve case 31. A spring member 53 interposed between the valve case 31 and the compression side air chamber forming member 51 is housed in the compression side air chamber G4. Further, the compression side air chamber G4 communicates with a space filled with a gas above the liquid level of the hydraulic oil O in the tank T.

The valve case 31 in the seismic isolation damper D24 includes a guide shaft 31a that projects toward the compression side chamber R2 side, and the damping passage 33 and the suction passage 35 that communicate the compression side chamber R2 and the tank T are guide shafts 31a. It is open at the tip of the valve, and care is taken not to be blocked by the compression side air chamber forming member 51.

In this way, in the seismic isolation damper D24, the extension side air chamber G3 and the compression side air chamber R4 are always in the tank T even if the seismic isolation damper D24 expands and contracts and the liquid level of the hydraulic oil O in the tank T rises and falls. It is designed to communicate with the space filled with the gas of. In this way, the extension side air chamber G3 and the compression side air chamber R4 are always in communication with each other through the tank T so that the internal pressures are equal. Further, the spring member 52 and the spring member 53 are also coil springs, and when the piston 2 returns to the neutral position with respect to the cylinder 1 after the seismic isolation damper D24 expands and contracts, the extension side air chamber forming member 50 The compression side air chamber forming member 51 is returned to its original position.

In the seismic isolation damper D24 configured in this way, the extension side air chamber forming member 50 can move to the left until the spring member 52 contracts to the maximum. Then, until the movement distance of the piston 2 from the neutral position to the left in FIG. 11 reaches a predetermined stroke range, the spring member 52 does not contract most even if the extension side air chamber forming member 50 moves to the left. When the predetermined stroke range is reached, the spring member 52 contracts most and the movement of the extension side air chamber forming member 50 to the left is restricted. That is, the spring member 52 not only returns the extension side air chamber forming member 50 to the original position but also functions as a stopper, but a stopper may be provided as in the seismic isolation damper D12.

Therefore, when the seismic isolation damper D24 extends and the piston 2 strokes from the neutral position within a predetermined stroke range, the extension side air chamber forming member 50 moves in the same direction according to the movement of the piston 2. .. Further, the compression side air chamber forming member 51 moves in the same direction according to the movement of the piston 2. The extension side air chamber G3 and the compression side air chamber G4 are communicated with each other via the tank T, and even if the extension side air chamber G3 is compressed by the movement of the extension side air chamber forming member 50 to the left, the compression side air chamber G4 Is expanded by moving the compression side air chamber forming member 51 to the left. When the seismic isolation damper D24 is extended in this way, the total volume of the space filled with gas in the extension side air chamber G3, the compression side air chamber G4, and the tank T, that is, the total volume of the total air chamber is determined by the rod 3. It increases by the volume that exits the cylinder 1. Therefore, if the pressure loss when the fluid passes through the damping passage 5 is ignored, the amount of pressure increase in the extension side chamber R1 changes from the pressure increase due to the force received by the compression of the spring member 52 to the increase in all air chambers due to the balance of forces. It is the amount after deducting the corresponding pressure drop. On the other hand, if the pressure loss when the fluid passes through the damping passage 5 is ignored, the amount of pressure decrease in the compression side chamber R2 is due to the pressure decrease due to the force received by the extension of the spring member 53 and the increase in the entire air chamber. It is the sum of the corresponding pressure reduction. From the above, if the spring constants of the spring members 52 and 53 are reduced, the pressure difference between the extension side chamber R1 and the compression side chamber R2 becomes very small, and in the seismic isolation damper D24, the piston 2 is within a predetermined stroke range from the neutral position. When stroking, it exerts very little damping force.

On the other hand, when the moving distance of the piston 2 from the neutral position exceeds a predetermined stroke range, the extension side air chamber forming member 50 cannot move in the direction of further compressing the extension side air chamber G3 due to the maximum compression of the spring member 52. .. Then, the hydraulic oil O in the extension side chamber R1 is compressed by the movement of the piston 2, and the pressure in the space filled with the hydraulic oil O in the extension side chamber R1 rises significantly, passes through the damping passage 5, and is compressed from the extension side chamber R1. The amount of hydraulic oil that moves to the chamber R2 increases. Further, the compression side air chamber forming member 51 moves in the same direction according to the movement of the piston 2, but the compression side air chamber G4 is communicated with the tank T, and the rod 3 is connected to the compression side chamber R2 through the suction passage 35. A volume of hydraulic oil that exits the cylinder 1 is supplied. Therefore, the pressure in the compression side chamber R2 is lower than that in the tank T by the force acting by the extension of the spring member 53. Therefore, when the moving distance of the piston 2 from the neutral position exceeds a predetermined stroke range, the pressure difference between the extension side chamber R1 and the compression side chamber R2 becomes large, and the seismic isolation damper D24 exerts its own extension by exerting a high damping force. Will interfere.

Further, in the seismic isolation damper D24, the compression side air chamber forming member 51 can move to the right until the spring member 53 contracts to the maximum. Then, until the movement distance of the piston 2 from the neutral position to the right in FIG. 11 reaches a predetermined stroke range, the spring member 53 does not contract most even if the compression side air chamber forming member 51 moves to the right, and the spring member 53 does not contract most. When the stroke range is reached, the spring member 53 contracts most and the movement of the compression side air chamber forming member 51 to the right is restricted. That is, the spring member 53 not only returns the compression side air chamber forming member 51 to the original position but also functions as a stopper, but a stopper may be provided as in the seismic isolation damper D12.

Therefore, when the seismic isolation damper D24 contracts and the piston 2 strokes from the neutral position to less than a predetermined stroke range, the compression side air chamber forming member 51 moves in the same direction according to the movement of the piston 2. Further, the extension side air chamber forming member 50 moves in the same direction according to the movement of the piston 2. The extension side air chamber G3 and the compression side air chamber G4 are communicated with each other via the tank T, and even if the compression side air chamber G4 is compressed by the movement of the compression side air chamber forming member 51 to the right, the extension side air chamber G3 remains. It is enlarged by moving the extensor air chamber forming member 50 to the right. Therefore, when the seismic isolation damper D24 contracts, the rod 3 is the cylinder for the total volume of the space filled with gas in the extension side air chamber G3, the compression side air chamber G4, and the tank T, that is, the volume of the total air chamber. The volume that invades 1 is reduced. Therefore, if the pressure loss when the fluid passes through the damping passages 5 and 33 is ignored, the amount of pressure increase in the compression side chamber R2 is due to the pressure increase due to the force received by the compression of the spring member 53. It is the sum of the pressure increase commensurate with the decrease. On the other hand, if the pressure loss when the fluid passes through the damping passages 5 and 33 is ignored, the amount of pressure decrease in the extension side chamber R1 is due to the pressure decrease due to the force received by the extension of the spring member 52 due to the balance of the force. The amount is obtained by subtracting the pressure increase commensurate with the decrease. From the above, if the spring constants of the spring members 52 and 53 are reduced, the pressure difference between the compression side chamber R2 and the extension side chamber R1 becomes very small, and the seismic isolation damper D24 has the piston 2 within a predetermined stroke range from the neutral position. When stroking, it exerts very little damping force.

On the other hand, when the moving distance of the piston 2 from the neutral position is equal to or greater than the predetermined stroke range, the compression side air chamber forming member 51 cannot move in the direction of further compressing the compression side air chamber G4 due to the maximum compression of the spring member 53. Then, the hydraulic oil O in the compression side chamber R2 is compressed by the movement of the piston 2, and the pressure in the space filled with the hydraulic oil O in the compression side chamber R2 rises significantly, and the hydraulic oil passes through the damping passage 5 and the damping passage 33. The amount will increase. Further, the extension side air chamber forming member 50 moves in the same direction according to the movement of the piston 2, but the extension side air chamber G3 is communicated with the tank T. Therefore, the pressure in the extension side chamber R1 is lower than that in the tank T by the force acting by the extension of the spring member 52. Therefore, when the moving distance of the piston 2 from the neutral position exceeds a predetermined stroke range, the pressure difference between the compression side chamber R2 and the extension side chamber R1 becomes large, and the seismic isolation damper D24 exerts its own extension by exerting a high damping force. Will interfere.

In the seismic isolation damper D24, the extension side air chamber G3 and the compression side air chamber G4 are communicated with each other in the space filled with the gas in the tank T to increase the volume of the entire air chamber. And the pressure fluctuation in the compression side air chamber G4 is reduced. Therefore, the seismic isolation damper D24 of this example can further reduce the damping force exerted when the piston 2 strokes within the range in which the damping force is desired to be reduced. It is also possible to adopt a structure in which the extension side air chamber G3 and the compression side air chamber G4 do not communicate with the tank T, and the extension side air chamber G3 and the compression side air chamber G4 may be formed between the extension side air chamber G3 and the compression side air chamber G4.

Further, in this seismic isolation damper D24, the extension side air chamber forming member 50 can move to the left until the spring member 52 is maximally compressed at the time of extension, so that a low damping force is exhibited, and the spring member 53 is most compressed at the time of contraction. Until this is done, the compression side air chamber forming member 51 can move to the right, so that a low damping force is exhibited. Therefore, the spring members 52 and 53 can switch the damping force between high and low. Therefore, although the predetermined stroke range can be easily set by the close contact length of the spring members 52 and 53, the predetermined stroke range may be set by separately providing a stopper. Further, the spring members 52 and 53 are set as a coil spring whose pitch changes in the middle or a two-stage spring in which coil springs having different pitches are arranged in series so that the spring constant becomes large when the portion having a narrow pitch is maximally compressed. The movement of the extension side air chamber forming member 50 and the compression side air chamber forming member 51 may be greatly hindered by the maximum compression of the portion having a narrow pitch. In this way, the damping force of the seismic isolation damper 24 can be increased when the portion having a narrow pitch is maximally compressed, and a predetermined stroke range can be set. The spring members 52 and 53 may be made of an elastic body such as rubber in addition to the coil spring. When the spring members 52 and 53 are omitted, the extension side air chamber forming member 50 and the compression side air chamber forming member 51 are affected by the pressure in the extension side air chamber G3 and the compression side air chamber G4 in the state where the piston 2 is in the neutral position. A predetermined stroke range may be set while allowing the and to return to the original position.

Further, a space that functions as a part of the extension side chamber R1 and the compression side chamber R2 is formed in the rod 3 or the piston 2 in the seismic isolation dampers D21, D22, D23 of the second embodiment, and the extension side is formed in each of these spaces. The air chamber forming member 19 and the compression side air chamber forming member 20 may be inserted to form the extension side air chamber G1 and the compression side air chamber G2.

Although the preferred embodiments of the present invention have been described in detail above, modifications, modifications and changes can be made as long as they do not deviate from the claims.

1 ... Cylinder, 2 ... Piston, 3 ... Rod, 7 ... First passage, 8, 37, 39 ... Adjusting valve, 10 ... Valve body, 11, 12 ... Spring, 13, 19, 21, 50 ... extension side air chamber forming member, 14, 20, 22, 51 ... compression side air chamber forming member, 36 ... second passage, 38 ... third passage , D11, D12, D13, D14, D15, D21, D22, D23, D24 ... Seismic isolation damper, G1, G3 ... Extension side air chamber, G2, G4 ... Pressure side air chamber, O ...・ Hydraulic oil (hydraulic liquid), R1 ・ ・ ・ extension side chamber, R2 ・ ・ ・ compression side chamber, T ・ ・ ・ tank

Claims (7)

Cylinder and
A piston that is slidably inserted into the cylinder to separate the extension side chamber and the compression side chamber,
A rod that is inserted into the cylinder and connected to the piston,
A working liquid having a volume smaller than the volume of the extension side chamber and the compression side chamber filled in the extension side chamber and the compression side chamber, respectively.
The isolation is characterized in that the piston is arranged in a neutral position with respect to the cylinder and is provided with a liquid level adjusting portion that equalizes the height of the liquid level of the working liquid in the extension side chamber and the compression side chamber when the piston is stationary. Seismic isolation. The liquid level adjusting unit has a first passage that communicates the extension side chamber and the compression side chamber.
The first passage has the width in the vertical direction of the first passage when the piston is in the neutral position and the liquid levels of the working liquids filled in the extension side chamber and the compression side chamber are equal to each other. The seismic isolation damper according to claim 1 , wherein the damper is installed so that the liquid level is located. The liquid level adjusting unit has a first passage that communicates the extension side chamber and the compression side chamber, and an adjustment valve that opens and closes the first passage.
The adjusting valve has a valve body and a spring that biases the valve body to position the valve body at a valve opening position, and opens when the pressure difference between the extension side chamber and the compression side chamber becomes less than a predetermined pressure. The seismic isolation damper according to claim 1 , wherein the damper is made to speak. The volume of the working liquid filled in the extension side chamber and the compression side chamber is one half or more of the volume of the extension side chamber and the compression side chamber when the piston is in a neutral position with respect to the cylinder. The seismic isolation damper according to any one of claims 1 to 3, which is characteristic. Any of claims 1 to 4, wherein the generated damping force is lowered when the moving distance of the piston from the neutral position of the piston is less than the predetermined stroke range with respect to the cylinder, and the generated damping force is increased when the moving distance of the piston is less than the predetermined stroke range. The seismic isolation damper described in item 1. A tank provided outside the cylinder to store the working liquid and compensate for the volume of the rod entering and exiting the cylinder is provided.
The liquid level adjusting unit includes a second passage that communicates the extension side chamber and the tank, a third passage that communicates the compression side chamber and the tank, a first adjustment valve that opens and closes the second passage, and the said. It has a second regulating valve that opens and closes the third passage,
The first and second regulating valves have a valve body and a spring that biases the valve body to position the valve body at a valve opening position, and the pressure difference between the extension side chamber and the compression side chamber is large. The seismic isolation damper according to claim 1 , wherein the valve is opened when the pressure becomes less than a predetermined pressure. A tank provided outside the cylinder to store the working liquid and compensate for the volume of the rod entering and exiting the cylinder is provided.
The liquid level adjusting unit, before a third passage communicating with said tank and second passage or said compression-side chamber communicating with said with lymphotoxin side chamber tank, the first passage and the second passage or the third It has a regulating valve that opens and closes the passage,
The adjusting valve has a valve body and a spring that biases the valve body to position the valve body at a valve opening position, and opens when the pressure difference between the extension side chamber and the compression side chamber becomes less than a predetermined pressure. The seismic isolation damper according to claim 1 , wherein the damper is made to speak.

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