JP2018003853A - Base isolation damper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a damper capable of exhibiting high attenuation force against large amplitude of earthquake vibration without impairing a base isolation effect.SOLUTION: A base isolation damper D includes a cylinder 1, a piston 2 defining the cylinder 1 into an expansion side chamber R1 and a pressure side chamber R2, and a rod 3. The damper has an attenuation force characteristic of: outputting low attenuation force in a case where a piston speed is in a low speed region; outputting high attenuation force in a case where the piston speed is in a high speed region; and increasing attenuation force from the low attenuation force to the high attenuation force according to increase of the piston speed, in a case where the piston speed is in an intermediate speed region between the low speed region and the high speed region.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a seismic isolation damper.

  The seismic isolation device is equipped with a support device such as a ball isolator or rubber interposed between the ground and the structure, and supports the structure so that it can be displaced relative to the ground, and transmits seismic motion to the structure. It is designed to be insulated. In addition to the support device as described above, the seismic isolation device may include a damper interposed between the ground and the structure. The vibration of the structure is attenuated by the damping force generated by the damper. The vibration of the structure is suppressed.

  In this way, the seismic isolation damper used in combination with the seismic isolation device can suppress the vibration of the structure, but if the damping force of the damper is excessive for the large vibration that the piston speed reaches the high speed range, the structure will have a large vibration. There is a possibility that pillars and beams will be deformed due to acceleration.

  Therefore, the seismic isolation damper is provided with a pressure regulating valve and a relief valve. As shown in FIG. 6, when the piston speed increases, the relief valve opens to reduce the damping coefficient, thereby increasing the speed. The excessive damping force is prevented, and the structure is protected (see, for example, Patent Document 1).

JP 2005-248520 A

  However, the above-described damper may obstruct the seismic isolation effect of the seismic isolation device. The damping force characteristic of the damper described above (the damping force characteristic generated by the damper with respect to the piston speed) is the damping coefficient of the pressure regulating valve until the damping coefficient is switched to a small value, that is, until the relief valve is opened. The amount of increase in damping force is large with increasing piston speed.

  Then, even if the piston speed is in a low speed region, the damping force generated by the damper becomes excessive, and the seismic motion is transmitted to the structure, which may hinder the seismic isolation effect of the seismic isolation device.

  That said, the following problems arise when trying to obtain a seismic isolation effect by reducing the damping coefficient until the relief valve is opened. Specifically, when a large-amplitude earthquake motion occurs, this time, the damping force is insufficient and the damper is expanded or contracted to the maximum extent, or the structure collides with a stopper that suppresses the displacement of the structure relative to the ground. As a result, shocking acceleration may be applied to the structure.

  Therefore, the present invention has been developed to solve the above-mentioned problems, and its purpose is not to impair the seismic isolation effect and to provide high damping for large-amplitude earthquake motions in which the piston speed reaches a high speed range. It is to provide a damper that can exert its power.

  In order to achieve the above object, a seismic isolation damper according to the present invention includes a cylinder, a piston that divides the inside of the cylinder into an extension side chamber and a compression side chamber, and a rod. Outputs a low damping force, outputs a high damping force when the piston speed is in the high speed range, and starts with a low damping force as the piston speed increases in the medium speed range between the low speed range and the high speed range. It has a damping force characteristic that increases the damping force to a high damping force. Therefore, when the piston speed is low, the seismic isolation damper exhibits only a low damping force and does not hinder vibration insulation to the structure, and large vibrations that reach a high piston speed act on the structure. High damping force can be demonstrated in the scene.

  The seismic isolation damper according to claim 2 includes a pressure regulating valve provided in each of the expansion side passage, the pressure side passage and the discharge passage and a relief valve arranged in parallel with the pressure regulating valve, and the piston speed is low at the pressure regulating valve. In addition to obtaining a damping force characteristic from the high speed range to the medium speed range, the piston speed is obtained by the relief valve in the high speed range. The seismic isolation damper configured as described above can realize a damping force characteristic that changes from a low damping force to a high damping force according to the piston speed with a simple configuration.

  Therefore, according to the seismic isolation damper of the present invention, it is possible to exhibit a high damping force against large-amplitude earthquake motions in which the piston speed reaches a high speed range without impairing the seismic isolation effect.

It is a schematic sectional drawing of the seismic isolation damper in one embodiment. It is a pressure flow characteristic figure of a pressure regulation valve. It is sectional drawing in an example of a pressure regulation valve. It is a pressure flow characteristic figure of an attenuation part. It is a damping-force characteristic figure of a seismic isolation damper. It is a damping-force characteristic figure of the existing damper. It is the figure which showed the response with respect to the seismic wave of a building at the time of inputting the seismic wave supposing the Nankai Trough earthquake. It is the figure which showed the response with respect to the earthquake wave of the building at the time of inputting the earthquake wave which assumed the earthquake (level 3B) which made the Uemachi fault the epicenter. It is the figure which showed the response with respect to the earthquake wave of a building at the time of inputting the earthquake wave which assumed the earthquake (level 3C) which made the Uemachi fault an epicenter. It is a schematic sectional drawing of the seismic isolation damper in one modification of one embodiment.

  The present invention will be described below based on the illustrated embodiment. As shown in FIG. 1, a seismic isolation damper D according to an embodiment includes a cylinder 1 and a piston that is slidably inserted into the cylinder 1 and divides the cylinder 1 into an extension side chamber R1 and a pressure side chamber R2. 2, a rod 3 movably inserted into the cylinder 1 and connected to the piston 2, an extension side passage 4, a pressure side passage 5, a reservoir R, and a pressure side chamber communicating with the extension side chamber R1 and the pressure side chamber R2. A discharge passage 6 that communicates R2 and the reservoir R, and attenuation portions V1, V2, and V3 provided in the extension side passage 4, the pressure side passage 5, and the discharge passage 6, respectively, are configured.

  Further, although not shown, the seismic isolation damper D is used by being interposed with an elastic body such as a ball isolator or laminated rubber between the ground and the structure, and functions as a part of the seismic isolation device. .

  Hereinafter, each part will be described. As described above, the piston 2 is inserted into the cylinder 1 so as to be movable in the axial direction. The cylinder 1 is partitioned by the piston 2 into an extension side chamber R1 and a pressure side chamber R2. An outer cylinder 7 that covers the cylinder 1 is provided on the outer peripheral side of the cylinder 1, and a reservoir R is formed by an annular gap between the cylinder 1 and the outer cylinder 7. The left end of the outer cylinder 7 in FIG. 1 is closed by an annular rod guide 8 through which the rod 3 is inserted on the inner periphery and guides the axial movement of the rod 3. The rod 3 is inserted into the cylinder 1, one end is connected to the piston 2, and the other end protrudes outside the cylinder 1.

  Further, the right end of the cylinder 1 in FIG. 1 is closed by a bottom member 9, and the right end of the outer cylinder 7 in FIG. 1 is closed by a lid 10. The cylinder 1 is housed and fixed in the outer cylinder 7 by being sandwiched by the rod guide 8 and the lid 10 fixed to both ends of the outer cylinder 7 together with the bottom member 9.

  In this case, the extension side chamber R1 and the pressure side chamber R2 are filled with hydraulic oil, and the hydraulic oil is also stored in the reservoir R. In this example, the working oil is used as the working medium of the seismic isolation damper D, but a liquid other than the working oil may be used, and water, an aqueous solution, or the like may be used.

  The piston 2 is provided with an extension side passage 4 and a pressure side passage 5 that communicate the extension side chamber R1 and the pressure side chamber R2. The expansion side passage 4 is provided with an attenuation portion V1, and the compression side passage 5 is provided with an attenuation portion V2. The damping part V1 includes a pressure regulating valve PV and a relief valve RV arranged in parallel with the pressure regulating valve PV, and allows only the flow of hydraulic oil passing through the expansion side passage 4 from the expansion side chamber R1 to the pressure side chamber R2. Resistance is applied to the flow, and the extension side passage 4 is set as a one-way passage. The damping part V2 includes a pressure regulating valve PV and a relief valve RV arranged in parallel with the pressure regulating valve PV in the same manner as the damping part V1, and only the flow of hydraulic fluid that passes through the pressure side passage 5 from the pressure side chamber R2 to the expansion side chamber R1. The pressure side passage 5 is set as a one-way passage while resistance is given to the flow while allowing the pressure. The expansion side passage 4 and the pressure side passage 5 are both provided in the piston 2 in this example, but the installation location is not limited to the piston 2, and for example, the expansion side chamber R1 and the pressure side chamber R2 are provided outside the cylinder 1. It may be configured to communicate.

  The bottom member 9 is provided with a discharge passage 6 and a suction passage 11 that allow the pressure side chamber R2 and the reservoir R to communicate with each other. The discharge passage 6 is provided with an attenuation portion V3. Similarly to the damping parts V1 and V2, the damping part V3 includes a pressure regulating valve PV and a relief valve RV parallel to the pressure regulating valve PV. The damping part V3 passes through the discharge passage 6 from the pressure side chamber R2 to the reservoir R. A resistance is given to this flow while allowing only the flow, and the discharge passage 6 is set as a one-way passage. The suction passage 11 is provided with a check valve 12 that allows only the flow of hydraulic oil from the reservoir R to the pressure side chamber R2. The suction passage 11 is operated by the check valve 12 from the reservoir R to the pressure side chamber R2. It is set as a one-way passage that allows only oil flow. The discharge passage 6 and the suction passage 11 are both provided in the bottom member 9 in this example, but the installation location is not limited to the bottom member 9.

  When the seismic isolation damper D configured as described above is extended, the extension side chamber R1 is compressed and the compression side chamber R2 is expanded by the movement of the piston 2 leftward in FIG. It moves from the extension side chamber R1 to the compression side chamber R2 via the side passage 4. Further, when the seismic isolation damper D is extended, the rod 3 is withdrawn from the cylinder 1, so that the volume of hydraulic oil withdrawn from the cylinder 1 of the rod 3 is supplied from the reservoir R into the cylinder 1 through the suction passage 11. The And since the attenuation part V1 gives resistance with respect to the flow of the hydraulic fluid which goes to the compression side chamber R2 from the extension side chamber R1, the pressure in the extension side chamber R1 rises and a difference arises in the pressure of the extension side chamber R1 and the compression side chamber R2. Thus, the seismic isolation damper D exhibits an extension side damping force that suppresses extension.

  When the seismic isolation damper D contracts, the compression side chamber R2 is compressed and the expansion side chamber R1 is expanded by the movement of the piston 2 to the right in FIG. It moves from the compression side chamber R2 to the extension side chamber R1. Further, when the seismic isolation damper D contracts, the rod 3 enters the cylinder 1, so that the volume of hydraulic oil that has entered the cylinder 1 of the rod 3 enters the reservoir R from the cylinder 1 through the discharge passage 6. Discharged. The damping part V2 gives resistance to the flow of hydraulic oil from the pressure side chamber R2 to the expansion side chamber R1, and the damping part V3 gives resistance to the flow of hydraulic oil from the pressure side chamber R2 to the reservoir R. As a result, the pressure in the compression side chamber R2 rises and a difference occurs between the pressures in the compression side chamber R2 and the expansion side chamber R1, and the seismic isolation damper D exhibits a compression side damping force that suppresses the contraction.

  Next, the attenuation parts V1, V2, and V3 will be described. Each of the damping parts V1, V2, and V3 includes a pressure regulating valve PV having the same configuration and a relief valve RV arranged in parallel with the pressure regulating valve PV. The pressure regulating valve PV is energized by a spring and is set to a normally closed type, and changes the valve opening degree according to the upstream pressure to give resistance to the flow of hydraulic oil. Here, the flow rate that passes through the damping parts V1, V2, and V3 is proportional to the piston speed that is the expansion and contraction speed when the seismic isolation damper D expands and contracts. Therefore, when the piston speed of the seismic isolation damper D is in the low speed range, the flow rate passing through the damping parts V1, V2, and V3 is small, and when the piston speed is in the high speed range, the flow rate is high and the piston speed is high. Is in the middle speed range that is intermediate between the low speed range and the high speed range, the flow rate is medium. As shown in FIG. 2, when the piston speed, which is the expansion / contraction speed of the seismic isolation damper D, is in the low speed range, the pressure flow characteristic of the pressure regulating valve PV is as follows. It shows characteristics with a small increase rate. On the other hand, the pressure flow characteristic of the pressure regulating valve PV shows a characteristic that when the piston speed reaches an intermediate speed range that is intermediate between the low speed range and the high speed range, the pressure greatly increases as the piston speed increases.

  The pressure regulating valve PV can be realized, for example, by adopting the structure disclosed in Japanese Patent No. 5508883. Specifically, as shown in FIG. 3, the pressure regulating valve PV includes a valve seat 100 provided in the middle of the passage, a valve body 101 that is movably accommodated in the passage, and is attached to and detached from the valve seat 100, A spring 102 that biases the body 101 toward the valve seat 100, and the valve body 101 abuts the valve body 101 when the amount of retraction from the valve seat 100 reaches a predetermined amount, and that of the valve body 101 from the valve seat 100 What is necessary is just to provide the stopper 103 which controls the above retreat. In the pressure regulating valve PV configured as described above, when the piston speed is low, the spring 102 is pressed and contracted by the upstream pressure, the valve body 101 is separated from the valve seat 100 and is opened, and the piston speed increases. Thus, the retraction amount from the valve seat 100 of the valve body 101 increases. Thus, when the piston speed is in the low speed region, the degree of valve opening increases as the piston speed increases, so the pressure flow characteristic of the pressure regulating valve PV shows a characteristic with a small slope as shown in FIG. On the other hand, when the piston speed increases and reaches the middle speed range, the retraction amount of the valve body 101 increases, and when the piston speed reaches the middle speed range, the valve body 101 abuts against the stopper 103 and that of the valve body 101 increases. The backward movement from the valve seat 100 is restricted. As described above, when the piston speed is in the middle speed range, the degree of valve opening remains constant even when the piston speed increases. Therefore, the pressure flow characteristic of the pressure regulating valve PV has an inclination as shown in FIG. Shows great characteristics. Therefore, when the piston speed increases from the low speed range to the medium speed range, the pressure regulating valve PV exhibits a characteristic that the inclination increases and the pressure increase increases. The pressure flow characteristic of the pressure regulating valve PV when the piston speed is in the middle speed range may be an orifice characteristic proportional to the square of the flow rate or a port characteristic proportional to the flow rate.

  In addition to restricting the amount of retraction of the valve body 101 by the stopper 103, a structure in which a throttle portion is provided downstream of the valve body 101 can be employed. In such a pressure regulating valve PV, when the flow path area between the valve seat 100 and the valve body 101 is equal to or larger than a predetermined value, the throttle portion is more than the resistance given to the flow of hydraulic oil between the valve seat 100 and the valve body 101. What is necessary is just to set so that the resistance given to the flow of hydraulic fluid may become large. The predetermined value can be set according to the flow passage area of the throttle portion. In the pressure regulating valve PV configured as described above, when the piston speed is low, the spring 102 is compressed and compressed by the upstream pressure, and the valve body 101 is moved to the valve seat 100. The valve is opened after being separated from the valve seat, and the retraction amount of the valve body 101 from the valve seat 100 increases as the piston speed increases. In this way, when the piston speed is in the low speed range, the degree of valve opening increases as the piston speed increases, so the pressure flow characteristic of the pressure regulating valve PV is a pressure against an increase in piston speed as shown in FIG. Shows a small increase in characteristics. On the other hand, when the piston speed increases and reaches the middle speed range, the retraction amount of the valve body 101 increases, the flow path area becomes equal to or larger than a predetermined value, and the characteristics of the throttle part appear, and the flow path area of the throttle part Since the pressure is constant, the pressure regulating valve PV exhibits a characteristic that the pressure increase increases with an increase in piston speed.

  On the other hand, the relief valve RV is opened when the differential pressure across the front and rear reaches a predetermined valve opening pressure, but the valve opening pressure is set so as not to open until the piston speed reaches the high speed range. The pressure-flow rate characteristic after the relief valve RV is opened is a characteristic in which the rate of increase in pressure is small with respect to the increase in piston speed. Therefore, the damping parts V1, V2, and V3, which are a combination of the pressure regulating valve PV and the relief valve RV, have the pressure flow characteristics shown in FIG. Specifically, the damping parts V1, V2, and V3 exhibit the characteristics of the pressure regulating valve PV when the piston speed is in the low speed range and the medium speed range, and the relief valve RV opens when the piston speed reaches the high speed range. Therefore, the characteristics of the relief valve RV are shown.

  The seismic isolation damper D is configured as described above. As described above, when the seismic isolation damper D extends, the hydraulic oil moves from the expansion side chamber R1 to the compression side chamber R2 via the expansion side passage 4. The volume of hydraulic oil that has retreated from the cylinder 1 of the rod 3 is supplied from the reservoir R into the cylinder 1 through the suction passage 11. And since the attenuation | damping part V1 gives resistance with respect to the flow of the hydraulic oil which goes to the compression side chamber R2 from the extension side chamber R1, thereby, the damper D for seismic isolation exhibits the extension side damping force which suppresses expansion | extension. Here, the pressure flow characteristics of the attenuation portion V1 are as shown in FIG. When the seismic isolation damper D extends, the flow rate that passes through the damping portion V1 is proportional to the piston speed that is the extension speed. Therefore, the damping force characteristic exhibited by the seismic isolation damper D is the same as the pressure flow characteristic of the damping part V1, as shown in FIG. Therefore, the seismic isolation damper D exhibits a low damping force with a small damping coefficient when the piston speed is low, and a small damping force increase rate with respect to an increase in piston speed. The seismic isolation damper D exhibits a damping force characteristic in which the damping coefficient increases as the piston speed increases from the low speed range to the medium speed range, and the damping force increases with increasing piston speed. . Furthermore, in the seismic isolation damper D, when the piston speed increases from the medium speed range to the high speed range, the relief valve RV opens, so that the damping coefficient is switched and becomes smaller. However, it shows a high damping force. When the piston speed is in the middle speed range, the seismic isolation damper D exhibits a damping force that changes from the low damping force to the high damping force as the piston speed increases. In FIG. 5, the boundary between the low speed region and the medium speed region is set to 60 cm / s, and the boundary between the medium speed region and the high speed region is set to 90 cm / s. What is necessary is just to set to the optimal value by the specification etc. of a thing.

  On the other hand, when the seismic isolation damper D contracts, the hydraulic oil moves from the compression side chamber R2 to the expansion side chamber R1 via the compression side passage 5, and the volume of hydraulic oil that has entered the cylinder 1 of the rod 3 passes through the discharge passage 6. Through the cylinder 1 and discharged to the reservoir R. The damping part V2 gives resistance to the flow of hydraulic oil from the pressure side chamber R2 to the expansion side chamber R1, and the damping part V3 gives resistance to the flow of hydraulic oil from the pressure side chamber R2 to the reservoir R. Here, the pressure flow characteristics of the attenuation parts V2 and V3 are also as shown in FIG. Therefore, as shown in FIG. 5, the seismic isolation damper D exhibits a low damping force with a small damping coefficient when the piston speed is low and a small increasing rate of the damping force with respect to an increase in the piston speed. The seismic isolation damper D exhibits a damping force characteristic in which the damping coefficient increases as the piston speed increases from the low speed range to the medium speed range, and the damping force increases with increasing piston speed. . Furthermore, in the seismic isolation damper D, when the piston speed increases from the medium speed range to the high speed range, the relief valve RV opens, so that the damping coefficient is switched and becomes smaller. However, it shows a high damping force. When the piston speed is in the middle speed range, the seismic isolation damper D exhibits a damping force that changes from the low damping force to the high damping force as the piston speed increases.

  In other words, in this seismic isolation damper D, when the piston speed is low, only a low damping force is exhibited, vibration insulation to the structure is not hindered, and a large vibration reaching a high piston speed occurs. Since a high damping force is exhibited in a scene acting on the structure, the vibration of the structure can be suppressed with a high damping force. Therefore, according to the seismic isolation damper D of the present invention, the seismic isolation effect is not impaired for small and medium-sized ground motions with relatively small shaking, and a high damping force is generated for large-amplitude ground motions. The vibration can be effectively suppressed. Moreover, since the seismic isolation damper D exhibits a high damping force against large-amplitude earthquake motion, the structure can be prevented from falling off from the seismic isolation device.

  In addition, when the piston speed is in the middle speed range, the seismic isolation damper D increases the damping coefficient and exhibits a damping force characteristic that changes from a low damping force to a high damping force. In switching to force, it is not necessary to apply a sudden acceleration fluctuation to the structure, and it is not necessary to protect the structure and apply an excessive load to people or equipment in the structure.

  Further, the seismic isolation damper D of the present example includes a pressure regulating valve PV provided in each of the expansion side passage 4, the pressure side passage 5, and the discharge passage 6, and a relief valve RV parallel to the pressure regulating valve PV, The pressure regulating valve obtains a damping force characteristic from a low speed region to a medium speed region, and the relief valve obtains a damping force characteristic in the high speed region. Since the seismic isolation damper D is thus configured, a damping force characteristic that changes from a low damping force to a high damping force according to the piston speed can be realized with a simple configuration.

  The boundary speed between the low speed range and the medium speed range of the piston speed, and the boundary speed between the medium speed and the high speed of the piston speed, which are boundaries where the damping force characteristics change, are the specifications required for the seismic isolation damper D. Can be arbitrarily set by the designer. If the boundary speed between the low speed region and the medium speed region of the piston speed is determined, the flow rate is determined, so that the retraction amount of the valve body 101 and the spring constant of the spring 102 that are regulated by the stopper 103 in the pressure regulating valve PV can be determined. If the boundary speed between the medium speed and the high speed of the piston speed is determined, the valve opening pressure of the relief valve RV can be determined.

  When an existing damper is installed between the elastically supported building (structure) and the ground, when the piston speed increases, the relief valve opens and the damping coefficient decreases (case 1). Instead, the comparison results of vibration analysis when the seismic isolation damper D of the present invention is incorporated (case 2) are shown below.

  As a premise for vibration analysis, the building is a 15-story reinforced concrete structure (RC structure), and the building is elastically supported with natural rubber laminated rubber and laminated rubber with lead plugs interposed between the building and the ground. Assume a structure that insulates the propagation of earthquake motion. The laminated rubber with a lead plug exhibits a function in which the laminated rubber functions as a spring and the lead plug attenuates elastic deformation of the laminated rubber.

In addition, vibration analysis was performed by inputting vibrations into the building and analyzing the response assuming earthquakes along the Nankai Trough as long-period ground motion and earthquakes (level 3B and level 3C) with the Uemachi fault as the direct earthquake. . The maximum acceleration of the seismic wave input to the building that assumed the Nankai Trough earthquake was 545.4 cm / s ² , the maximum velocity was 68.6 cm / s, and the duration was 655.3 s. The maximum acceleration of the seismic wave input to the building that assumed the earthquake of the Uemachi fault epicenter (level 3B) was 387.0 cm / s ² , the maximum velocity was 97.4 cm / s, and the duration was 41.0 s. The maximum acceleration of the seismic wave input to the building that assumed the earthquake of the Uemachi fault epicenter (level 3C) was 625.0 cm / s ² , the maximum velocity was 129.4 cm / s, and the duration was 41.0 s.

  The damping force characteristic of the above existing damper is as shown in FIG. 6. The damping coefficient is large in the low speed range, and the relief valve is opened when the piston speed exceeds 30 cm / s, and the damping coefficient is increased. This is a characteristic that decreases. The number of existing dampers and the number of seismic isolation dampers D was set so that the displacement of the first floor of the building would coincide with the input of the above-mentioned seismic waves. Specifically, the analysis is performed assuming that the number of seismic isolation dampers D is 10 and the number of existing dampers is 8.

  As an analysis result, the response to the earthquake wave of the building when the earthquake wave assuming the Nankai Trough earthquake is input is shown in Fig. 7, and the building wave when the earthquake assuming the Uemachi fault as the epicenter (level 3B) is input. FIG. 8 shows the response to the seismic wave, and FIG. 9 shows the response to the seismic wave of the building when the seismic wave assuming the Uemachi fault as the epicenter (level 3C) is input. In each figure, the response results for the absolute acceleration, displacement, and interlayer deformation angle of each layer of the building are graphed, and the results are shown in the same graph for easy comparison between Case 1 and Case 2.

  As shown in FIGS. 7 to 9, the seismic isolation damper D of the present invention is substantially smaller in absolute acceleration, displacement, and interlayer deformation angle than the existing damper for all seismic waves. It can be seen that the use of the seismic isolation damper D can effectively suppress the vibration of the building without impairing the seismic isolation effect. Further, it can be understood that if the seismic isolation damper D of the present invention is used in a seismic isolation device, damage to the building can be reduced against large amplitude earthquake motion. In addition, the seismic isolation damper D of the present invention can be used by being incorporated in the seismic isolation device of a new building, or can be used in place of the existing damper of the seismic isolation device of an existing building. The performance of the seismic isolation device can be improved.

  As shown in FIG. 10, the damping portions V1, V2, and V3 are arranged in parallel with a throttle valve O such as an orifice arranged in series and a low pressure relief valve LV, and with the throttle valve O and the low pressure relief valve LV. It may be configured with a high pressure relief valve HV. The damping parts V1, V2, and V3 in this case each include a throttle valve O, a low pressure relief valve LV, and a high pressure relief valve HV that have the same configuration. The low-pressure relief valve LV is energized by a spring and is set to a normally closed type, and changes the valve opening degree according to the upstream pressure to give resistance to the flow of hydraulic oil. The high-pressure relief valve HV is also energized by a spring and is set to a normally closed type, and the degree of valve opening is changed according to the upstream pressure to give resistance to the flow of hydraulic oil, but more than the low-pressure relief valve LV. The valve is set to open at a high valve opening pressure. The opening area of the throttle valve O is set to be narrower than the flow path area when the low pressure relief valve LV is opened to the maximum.

  The pressure flow characteristics of the damping portions V1, V2, and V3 configured as described above are as shown in FIG. 4. When the piston speed is in the low speed range, the low pressure relief valve LV is opened and the piston speed It shows the characteristic that the rate of increase in pressure is small with respect to the rise. The pressure flow characteristics of the damping parts V1, V2, and V3 indicate that when the piston speed reaches an intermediate speed range that is intermediate between the low speed range and the high speed range, the flow path area of the low pressure relief valve LV is larger than the opening area of the throttle valve O. Therefore, the characteristic of the throttle valve O appears, the damping coefficient increases, and the pressure increases greatly as the piston speed increases. Further, the pressure flow characteristics of the damping parts V1, V2, V3 are such that when the piston speed reaches a high speed range, the high pressure relief valve HV opens and the characteristics of the high pressure relief valve HV appear from the characteristics of the throttle valve O. Thus, the rate of increase in pressure is small with respect to the increase in piston speed.

  Even if the damping parts V1, V2, and V3 are configured in this way, the seismic isolation damper D exhibits substantially the same damping force characteristics as the damping parts V1, V2, and V3 that combine the pressure regulating valve PV and the relief valve RV. Therefore, even if the damping parts V1, V2, and V3 shown in FIG. 10 are used as described above, the seismic isolation damper D exhibits a low damping force when the piston speed is in the low speed range as shown in FIG. When the piston speed is in the middle speed range, it exhibits a damping force that changes from a low damping force to a high damping force as the piston speed increases, and when the piston speed is in the high speed range, the damping speed is high. Demonstrate power. Even in the seismic isolation damper D configured as described above, when the piston speed is low, only a low damping force is exhibited, vibration insulation to the structure is not hindered, and the piston speed reaches a high speed. Since a high damping force is exhibited in a scene where a large vibration acts on the structure, the vibration of the structure can be suppressed with a high damping force. Therefore, according to the seismic isolation damper D of the present invention, the seismic isolation effect is not impaired for small and medium-sized ground motions with relatively small shaking, and a high damping force is generated for large-amplitude ground motions. The vibration can be effectively suppressed.

  Although the preferred embodiments of the present invention have been described in detail above, modifications, changes and modifications can be made without departing from the scope of the claims.

DESCRIPTION OF SYMBOLS 1 ... Cylinder, 2 ... Piston, 3 ... Rod, 4 ... Extension side passage, 5 ... Pressure side passage, 6 ... Discharge passage, 7 ... Outer cylinder, 8 ... Rod guide, 9 ... bottom member, 10 ... lid, 11 ... suction passage, 12 ... check valve, 100 ... valve seat, 101 ... valve body, 102 ... spring 103, stopper, D, seismic isolation damper, HV ... high pressure relief valve, LV ... low pressure relief valve, O ... throttle valve, PV ... pressure regulating valve, R1 ... Extension side chamber, R2 ... Pressure side chamber, RV ... Relief valve

Claims (2)

A cylinder,
A piston that is slidably inserted into the cylinder and divides the cylinder into an extension side chamber and a pressure side chamber;
A rod inserted into the cylinder and coupled to the piston;
When the piston speed relative to the cylinder is in the low speed range, a low damping force is output. When the piston speed is in the high speed range, a high damping force is output. The piston speed is in the low speed range and the high speed range. In the middle speed range, the damping force characteristic is such that the damping force increases from a low damping force to a high damping force according to an increase in the piston speed with a damping coefficient larger than that of the low speed range and the high speed range. A seismic isolation damper. An extension side passage that allows only a flow of liquid from the extension side chamber to the pressure side chamber;
A pressure side passage that allows only a flow of liquid from the pressure side chamber toward the extension side chamber;
A reservoir,
A discharge passage that allows only the flow of liquid from the pressure side chamber toward the reservoir;
A pressure regulating valve provided in each of the extension side passage, the pressure side passage and the discharge passage, and a relief valve arranged in parallel with the pressure regulating valve;
With the pressure regulating valve, the piston speed obtains a damping force characteristic from the low speed range to the medium speed range,
The seismic isolation damper, wherein the relief valve obtains a damping force characteristic in the high speed range with the piston speed.

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