JP7504549B2 - Rotating Inertial Mass Damper - Google Patents

Description

The present invention relates to a rotary inertia mass damper that utilizes the rotary inertia of a rotary weight and the resistance of a viscous fluid.

In recent years, the application of damping devices to seismic isolation and vibration control structures has been proposed to improve the earthquake safety of buildings and other structures.

In a seismic isolation structure, an isolator is provided between a building and the ground as an insulator, preventing ground vibrations from being directly transmitted to the building and isolating the vibrations of the ground from those of the building. As a result, a seismic isolation structure can prevent resonance between the vibrations of the building and the vibrations of the ground, and the building will shake more slowly and with a longer period than the vibrations of the ground. In addition, a damping device is provided in a seismic isolation structure to absorb the vibration energy transmitted to the building through the isolator. Examples of damping devices include dampers. By providing a damping device, the long-period vibration energy separated by the isolator can be absorbed, and the building vibration can be brought to an early end. This can prevent the collapse of the building and damage to furniture and other items inside the building caused by an earthquake.

Unlike base isolation structures, vibration control structures have a building built on the ground, so ground vibrations are transmitted directly to the building. In vibration control structures, dampers are built into the building's frame as a damping device. These dampers absorb the vibration energy caused by earthquakes by transmitting the reaction force against deformations of the building caused by earthquakes to columns and beams.

An example of a damping device that can be applied to the seismic isolation structure or vibration control structure is a damper that uses a hydraulic motor, as described in Patent Document 1.

In the damper of Patent Document 1, a piston divides a cylinder into two pressure chambers, and the cylinder is filled with hydraulic oil as a viscous fluid. The two pressure chambers are connected to each other by an actuation flow path provided outside the cylinder. When an earthquake occurs, vibration energy caused by the earthquake is input as axial displacement to the piston via a rod connected to the building, causing the piston to reciprocate within the cylinder. As a result, the hydraulic oil in one of the pressure chambers is pressurized by the piston, and the pressurized hydraulic oil flows into the other pressure chamber through the actuation flow path. At this time, a large viscous resistance acts on the flow of hydraulic oil in the actuation flow path, so part of the vibration energy of the earthquake is attenuated by this viscous resistance.

A hydraulic motor is provided in the middle of the working flow path, and high-pressure hydraulic oil generated by the axial displacement of the piston rotates the hydraulic motor. A rotating weight is provided on the output shaft of the hydraulic motor, and the reciprocating motion of the piston in the cylinder is converted into the rotary reciprocating motion of the rotating weight. The rotary inertia corresponding to the rotation speed acts on the rotating weight as a reaction force. As a result, when the piston reciprocates in the cylinder in response to seismic motion acting on the building and the rotating weight repeatedly reverses, a reaction force corresponding to the equivalent mass of the rotating weight acts on the building. Therefore, in the damper disclosed in Patent Document 1, the viscous resistance generated by the flow of the hydraulic oil and the rotary inertia generated when the rotating weight reverses are used as a reaction force against the reciprocating motion of the piston to attenuate the vibration energy acting on the building.

Patent Publication No. 2020-029910

Since it is not possible to prevent mechanical oil leakage of high-pressure hydraulic oil in commonly used hydraulic motors, a structure is provided to recover leaked hydraulic oil using a drain circuit. The hydraulic oil recovered by the drain circuit is sent to an external storage tank together with the low-pressure hydraulic oil discharged from the hydraulic motor, and the hydraulic oil in the storage tank is re-pressurized by a hydraulic pump before being supplied to the hydraulic motor.

However, in the damper of Patent Document 1 mentioned above, a pair of pressure chambers partitioned by the piston are connected by the working flow path to form a closed circuit of hydraulic oil, and the hydraulic motor is provided in the middle of this closed circuit. Therefore, if mechanical oil leakage occurs from the hydraulic motor, the flow rate of hydraulic oil in the closed circuit will decrease, and there is a concern that the damping performance of the damper will not be achieved as designed. On the other hand, if the drain circuit is blocked, the leaked hydraulic oil will increase the internal pressure of the drain circuit, which could cause a malfunction of the hydraulic motor.

As a result, it was difficult to apply an existing hydraulic motor to the damper of Patent Document 1 and actually use it as a damper in the seismic isolation structure or vibration control structure.

The present invention was made in consideration of these problems, and its purpose is to provide a rotary inertia mass damper that can maintain the hydraulic oil flow rate as originally designed even over time when a damping device using a hydraulic motor is actually applied to a seismic isolation structure or vibration control structure, and can properly demonstrate damping performance.

The rotary inertia mass device of the present invention comprises a damper body having a cylinder filled with a viscous fluid, a piston that divides the inside of the cylinder into a pair of pressure chambers and moves within the cylinder, a movable rod that is connected to the piston and moves back and forth relative to the cylinder, an actuation flow path that moves the viscous fluid from the high-pressure pressure chamber to the low-pressure pressure chamber, a hydraulic motor that is provided in the actuation flow path and converts the flow of the viscous fluid into rotational motion, a rotary weight that is given a rotational force in response to the rotational motion of the hydraulic motor, a drain circuit that recovers the viscous fluid from the hydraulic motor, and a pair of return passages that communicate with the drain circuit and connect the high-pressure side actuation flow path to the low-pressure side actuation flow path via a check valve.

The inertial mass device of the present invention configured as described above allows the viscous fluid leaking from the hydraulic motor to flow from the drain circuit to the low-pressure pressure chamber, thereby preventing mechanical oil leakage and providing a rotary inertial mass damper that can properly demonstrate damping performance.

1A and 1B are schematic diagrams illustrating a first embodiment of a rotary inertia mass damper according to the present invention. FIG. 2 is a detailed schematic diagram of the drain circuit of the rotary inertia mass damper of the present invention; FIG. 4 is a schematic diagram showing a second embodiment of a rotary inertia mass damper of the present invention. FIG. 13 is a schematic diagram showing a third embodiment of a rotary inertia mass damper of the present invention.

The following describes in detail the rotary inertia mass damper to which the present invention is applied, with reference to the attached drawings.

Figure 1 is a schematic diagram for explaining the outline of a first embodiment of a rotary inertia mass damper to which the present invention is applied. This rotary inertia mass damper 1 includes a damper body 2 having a cylinder 20 inside, a movable rod 5, and a piston 51. When the rotary inertia mass damper 1 is applied to a seismic isolation structure, one of the damper body 2 and the movable rod 5 is provided on the building foundation to which the ground vibration is directly transmitted, and the other is provided on the building that is insulated from the ground vibration by an isolator. When an earthquake occurs, the rotary inertia mass damper 1 acts as a reaction force to return the positional displacement of the building and the building foundation separated by the isolator to their original position, and the long-period vibration occurring in the building can be converged early. When applied to a vibration control structure, it is incorporated into the frame of each floor of the building, and the reaction force against the deformation of the building caused by the earthquake is transmitted to the columns and beams, thereby attenuating the vibration energy caused by the earthquake.

The movable rod 5 is provided so as to penetrate the inside of the cylinder 20. An end of the movable rod 5 protrudes from the cylinder 20 to the outside. A ball joint 50 is provided at the protruding end. The ball joint 50 is used when connecting the movable rod 5 to a building foundation or a building. The movable rod 5 advances and retreats along the axial direction of the cylinder 20. The movable rod 5 reciprocates in the left-right direction of the page due to vibration energy caused by an earthquake.

The piston 51 is connected to the movable rod 5 and is disposed inside the cylinder 20. The piston 51 divides the inside of the cylinder 20 into a pair of pressure chambers 22a, 22b. The pressure chambers 22a and 22b are filled with a viscous fluid 21 such as oil. The piston 51 reciprocates along the axial direction of the cylinder 20 in response to the advancement and retreat of the movable rod 5. When an axial displacement of the movable rod 5 is input, the piston 51 connected to the movable rod 5 advances and retreats, and the viscous fluid 21 is pressurized by the piston 51.

The piston 51 has two through holes that communicate the pressure chamber 22a and the pressure chamber 22b. Each through hole is provided with a relief valve 52a that allows the viscous fluid 21 to flow from the pressure chamber 22a to the pressure chamber 22b, and a relief valve 52b that allows the viscous fluid 21 to flow from the pressure chamber 22b to the pressure chamber 22a. The relief valve 52a opens only when the viscous fluid 21 in the pressure chamber 22b is excessively pressurized and the internal pressure difference between the pressure chambers becomes a certain value or more. When the relief valve 52a opens, the viscous fluid 21 flows from the pressure chamber 22b to the pressure chamber 22 via the relief valve 52a. On the other hand, if the viscous fluid 21 in the pressure chamber 22a is excessively pressurized, the relief valve 52b opens and the viscous fluid 21 flows from the pressure chamber 22b to the pressure chamber 22a.

The damper body 2 has a ball joint 40 at one end in the longitudinal direction. The ball joint 40 is used when connecting to a building foundation or a building. When the rotational inertia mass damper 1 is used in a seismic isolation device, one of the ball joint 40 and the ball joint 50 is provided in the building foundation, and the other is provided in the building. When the rotational inertia mass damper 1 is used in a vibration control device, one of the ball joint 40 and the ball joint 50 is provided in a place or the like installed on an upper floor, and the other is provided in the structure of a lower floor. In this way, the damper is operated by utilizing the inter-story deformation between the upper and lower floors.

The damper body 2 is provided with an operating flow path 31 that connects the pressure chamber 22a and the pressure chamber 22b. As shown in FIG. 2, the operating flow path 31 is composed of an operating flow path 31a that connects the pressure chamber 22a and the hydraulic motor 30, and an operating flow path 31b that connects the pressure chamber 22b and the hydraulic motor 30. When the piston 51 applies pressure to one of the pressure chambers, the viscous fluid 21 in the pressurized pressure chamber is pushed out to the operating flow path 31 and moves into the unpressurized pressure chamber. That is, when the piston 51 moves and applies pressure to the viscous fluid 21, a reaction force based on the viscous resistance of the viscous fluid 21 acts against the pressure force of the piston 51. As a result, the axial displacement of the movable rod 5 is converted into pressure energy of the viscous fluid 21. On the other hand, when an axial displacement in the opposite direction is input to the piston 51, the low pressure side pressure chamber is pressurized, the pressure gradually increases, and the pressures in the low pressure side pressure chamber and the high pressure side pressure chamber are reversed. Therefore, in the rotary inertia mass damper 1, the movement direction of the piston 51 and the flow direction of the viscous fluid 21 change according to the advancement and retreat of the movable rod 5 to which the vibration energy due to the earthquake is input.

A hydraulic motor 30 is provided in the operating flow path 31. The hydraulic motor 30 can recover the viscous fluid 21 that has leaked inside. The hydraulic motor 30 generates a rotational motion by the flow of the viscous fluid 21. A rotary weight 60 is provided on the output shaft of the hydraulic motor 30. Therefore, when a rotational motion is generated by the hydraulic motor 30, the rotary weight 60 rotates in the direction of the rotational motion, generating an inertial mass in the rotational direction. On the other hand, when a reverse axial displacement is input to the piston 51, the direction of the viscous fluid 21 flowing through the operating flow path 31 is also reversed, and the rotational motion of the hydraulic motor 30 is also reversed. As a result, the inertial mass generated due to the rotation of the rotary weight 60 acts as a reaction force against the reverse flow energy of the viscous fluid 21. In other words, the equivalent mass of the rotary weight is amplified relative to the actual mass, and a damping effect is exhibited accordingly. In addition, a gear motor, an axial piston motor, etc. can be used as the hydraulic motor 30.

The hydraulic motor 30 is provided with a drain circuit 33. The drain circuit 33 is provided with a return passage 34 that is connected to the drain circuit 33. The return passage 34 connects the high-pressure side working flow path 31 to the low-pressure side working flow path 31. The return passage 34 is composed of a return passage 34a that connects the drain circuit 33 to the working flow path 31a, and a return passage 34b that connects the drain circuit 33 to the working flow path 31b. The return passages 34a and 34b are provided with check valves 32a and 32b, respectively. The check valves 31a and 31b do not open when the pressure difference between the working flow path 31 and the drain circuit 33 is below a certain value. As a result, the viscous fluid 21 that flows into the drain circuit 33 is blocked by the check valves 32a and 32b. When axial displacement is input by the piston 51, the pressure chamber on the low pressure side becomes negative pressure, making it easy for an internal pressure difference to occur between the working flow path 31 on the low pressure side and the drain circuit 33.

The check valve 32 is configured as a check valve that allows the viscous fluid 21 to flow only from the drain circuit 33 to the low-pressure pressure chamber when a pressure difference of a certain value or more occurs between the internal pressure of the working flow path 31 and the internal pressure of the drain circuit 33. For example, when the viscous fluid 21 moves from the pressure chamber 22a to the pressure chamber 22b, when the internal pressure difference between the working flow path 31b and the drain circuit 33 becomes a certain value or more, the check valve 32b opens toward the working flow path 31b side, and the check valve 32a does not open toward the working flow path 31a side. This allows the viscous fluid 21 to flow to the low-pressure pressure chamber without leaking the viscous fluid 21 leaking from the hydraulic motor 30 to the outside.

Next, we will explain the operation of the rotary inertia mass damper 1 of this embodiment configured in this way.

When an earthquake causes ground shaking, the ground shaking is converted into axial displacement of the movable rod 5 in the rotary inertia mass damper 1. The converted axial displacement is transmitted to the piston 51 connected to the movable rod 5. As a result, the piston 51 moves forward and backward along the axial direction of the cylinder 20, moving left and right on the page in FIG. 1.

First, if the movable rod 5 is displaced to the left on the paper, the viscous fluid 21 in the pressure chamber 22a is pressurized by the piston 51. The pressurized viscous fluid 21 is pushed out into the operating flow path 31, and flows from the operating flow path 31a through the hydraulic motor 30 to the operating flow path 31b and the pressure chamber 22b. Therefore, as the viscous fluid 21 is pressurized and flows into the operating flow path 31, a reaction force due to the viscous resistance of the viscous fluid 21 acts against the pressure force of the piston 51. When pressurized by the piston 51, the pressure chamber 22a is at high pressure, while the pressure chamber 22b is at low pressure.

The hydraulic motor 30 converts the pressure energy of the viscous fluid 21 into rotational motion as the viscous fluid 21 flows. The rotational motion generated by the hydraulic motor 30 is transmitted to a rotary weight 60 attached to the output shaft of the hydraulic motor, causing the rotary weight 60 to rotate.

Next, when an axial displacement in the opposite direction is input to the movable rod 5, the piston 51 advances toward the right of the page. When the piston 51 advances to the right, the pressure chamber 22b is pressurized, and the viscous fluid 21 in the pressure chamber 22b flows into the pressure chamber 22a through the operating flow paths 31b and 31a, similar to the movement when the pressure chamber 22a is pressurized. In other words, the flow direction of the viscous fluid 21 is reversed. As a result, the pressure chamber 22b, which was lowly pressurized, is pressurized by the piston 51, and the pressure gradually increases. On the other hand, the internal pressure of the pressure chamber 22a gradually decreases.

When the flow direction of the viscous fluid 21 is reversed, the direction of the rotational motion generated by the hydraulic motor 30 is also reversed, and the direction in which the rotational force is applied to the rotary weight 60 provided on the output shaft of the hydraulic motor 30 is also reversed. At this time, the rotary weight 60 rotates with the flow of the viscous fluid 21 moving from the pressure chamber 22a to the pressure chamber 22b, and this generates rotational inertia. Therefore, when a rotational force is applied in the opposite direction to the rotational direction, the rotary weight 60 exerts a reaction force due to the equivalent mass amplified according to the rotation speed against the flow of the viscous fluid 21. As a result, the rotary inertia mass damper 1 exerts an effect of damping vibration energy caused by earthquakes due to the rotary inertia mass effect of the rotary weight 60 in addition to the reaction force due to the viscous resistance of the viscous fluid 21.

If the piston 51 moves with an extremely large acceleration and the pressure in the pressure chamber 22a becomes excessively high, the relief valve 52b opens and the viscous fluid 21 in the pressure chamber 22a flows into the pressure chamber 22b through a through hole provided in the piston 51, thereby adjusting the pressure. On the other hand, if the pressure in the pressure chamber 22b becomes excessively high, the relief valve 52a opens and the viscous fluid 21 in the pressure chamber 22b moves into the pressure chamber 11a through a through hole provided in the piston 51.

When the hydraulic motor 30 is operating, mechanical leakage of the viscous fluid 21 occurs and is recovered by the hydraulic motor 30. The recovered viscous fluid 21 flows into the drain circuit 33 and is blocked by the check valve 32. When the pressurizing force of the piston 51 is excessively large and the viscous fluid 21 leaking from the hydraulic motor 30 causes high pressure in the drain circuit 33, and a pressure difference of a certain value or more is generated between the internal pressure of the drain circuit 33 and the internal pressure of the working flow path 31, the check valve 32b opens. When the check valve 32b opens, the viscous fluid 21 that was blocked in the drain circuit 33 flows toward the low-pressure side working flow path 31b. As a result, the pressure in the drain circuit 33 decreases. For example, when the pressure chamber 22a is pressurized and the viscous fluid 21 is moving from the pressure chamber 22a to the pressure chamber 22b, the check valve 32b opens when the internal pressure difference between the drain circuit 33 and the working flow path 31b reaches or exceeds a certain value.

On the other hand, even when the pressure chamber 22b is pressurized and the viscous fluid 21 flows from the pressure chamber 22b to the pressure chamber 22a, the pressure in the drain circuit 33 may become high due to the viscous fluid 21 leaking from the hydraulic motor 30. In this case, too, when the internal pressure difference between the drain circuit 33 and the working flow path 31a exceeds a certain value, the check valve 32a opens and the viscous fluid 21 in the drain circuit 33 flows into the working flow path 31a. This causes the pressure in the drain circuit 33 to decrease.

The rotary inertia mass damper of the present invention configured as described above can prevent the viscous fluid 21 from leaking from the hydraulic motor 30 when vibration energy due to an earthquake is input, and the viscous fluid 21 can be returned to the low pressure side pressure chamber via the check valve 32 from the drain circuit 33 provided in the hydraulic motor 30, thereby preventing the viscous fluid 21 from leaking outside the rotary inertia mass damper 1.

Therefore, even if there is a mechanical oil leak from the hydraulic motor 30 in the rotary inertia mass damper 1, which is configured as a closed circuit in which the volume of the viscous fluid 21 in the cylinder 20 is fixed, the leaked viscous fluid 21 can be returned to the low-pressure pressure chamber, preventing a decrease in the viscous fluid 21 in the entire damper. Therefore, even when a rotary inertia mass damper using an existing hydraulic motor is actually applied to a seismic isolation device or vibration control device, it is possible to maintain the flow rate of the viscous fluid as originally designed, and the damping performance can be appropriately demonstrated.

Figure 3 is a schematic diagram showing a second embodiment of the rotary inertia mass damper 1 to which this embodiment is applied.

The rotary inertia mass damper of the second embodiment is the rotary inertia mass damper of the first embodiment with an accumulator added. Since the configuration other than these is the same as the configuration of the first embodiment described above, the same reference numerals as in the first embodiment are used in Figure 3 and detailed description is omitted.

As shown in FIG. 3, an accumulator 70 is provided in the drain circuit 33 extending from the hydraulic motor 30. The accumulator 70 has a pressure accumulation function of recovering the viscous fluid 21 that has flowed into the drain circuit 33 and maintaining the pressure of the recovered viscous fluid 21. Therefore, the accumulator 70 maintains the pressure in the drain circuit 33 at a constant value.

Next, we will explain the operation of the rotary inertia mass damper of the second embodiment.

The basic operation of the rotary inertia mass damper of the second embodiment is the same as that of the rotary inertia mass damper of the first embodiment described above. Therefore, the same operation will be explained in a simplified manner. When an earthquake occurs, the rotary inertia mass damper 1 is converted into an axial displacement of the movable rod 5, and the piston 51 connected to the movable rod 5 moves forward and backward within the cylinder 20.

When the pressure chamber 22a is pressurized by the advancement of the piston 51, the viscous fluid 21 filled in the pressure chamber 22a is pressurized and the viscous fluid 21 is pushed out into the actuation flow path 31a. This causes the viscous fluid 21 to flow and move to the pressure chamber 22b via the hydraulic motor 30 and the actuation flow path 31b.

The hydraulic motor 30 converts the pressure energy of the viscous fluid 21 into rotational motion as the viscous fluid 21 flows. The rotational motion is transmitted to a rotary weight 60 attached to the output shaft of the hydraulic motor 30, causing the rotary weight 60 to rotate.

If the pressure chamber 22a becomes excessively high, the relief valve 52a opens and the viscous fluid 21 flows from the pressure chamber 22a to the pressure chamber 22b. This allows the internal pressure to be reduced only if the pressure chamber 22a becomes excessively high.

The check valves 32a and 32b provided in the return passage 34 will not open unless there is a pressure difference of a certain value or more between the internal pressure of the drain circuit 33 and the working flow passage 31, so the viscous fluid 21 leaking from the hydraulic motor 30 is blocked by the check valves 32a and 32b. Up to this point, it is the same as the first embodiment.

The viscous fluid 21 that has flowed into the drain circuit 33 is temporarily collected and stored in the accumulator 70. That is, by temporarily holding the viscous fluid 21, which has a fixed volume in the rotary inertia mass damper 1, in the accumulator 70, the volume of the viscous fluid 21 in the device is temporarily reduced, thereby reducing the pressure of the entire device. In addition, even if the viscous fluid 21 expands in volume due to high heat, it can be collected and held in the accumulator 70. The viscous fluid 21 held in the accumulator 70 can be made to flow into the pressure chamber 22b with a time lag via the check valve 32b. Therefore, even if the pressure in the drain circuit 33 suddenly increases, the pressure in the drain circuit 33 can be reduced by temporarily collecting and holding the accumulator.

The operation of each component is the same even when the axial displacement of the movable rod 5 is input in the opposite direction. When the piston 51 pressurizes the pressure chamber 22b, the viscous fluid 21 filled in the pressure chamber 22b is pressurized and pushed out into the operating flow path 31b. The viscous fluid 21 then flows into the pressure chamber 22a via the hydraulic motor 30 and the operating flow path 31a. The hydraulic motor 30 then generates a rotational motion in response to the flow of the viscous fluid 21, and the rotary weight 60 attached to the output shaft of the hydraulic motor 30 rotates. At this time, the equivalent mass of the rotary weight 60 is amplified relative to the actual mass, so a reaction force corresponding to the amplified mass is generated.

According to the rotary inertia mass damper of the second embodiment configured as described above, when the pressure in the drain circuit 33 becomes high, the viscous fluid 21 can be temporarily held in the accumulator 70. The held viscous fluid 21 can then be made to flow to the low-pressure pressure chamber via the check valve 32. Therefore, even if the pressure in the drain circuit 33 suddenly becomes high, the pressure in the drain circuit 33 can be controlled by the actions of the accumulator and the check valve, and the thermal expansion of the viscous fluid 21 can be temporarily collected and held in the accumulator 70, ensuring greater safety. Therefore, even when a rotary inertia mass damper using an existing hydraulic motor is actually applied to a seismic isolation device or vibration control device, it is possible to appropriately exert the damping performance as originally designed and safely exert the damping effect on vibrations acting on buildings, etc.

Figure 4 is a schematic diagram showing a third embodiment of a rotary inertia mass damper 1 to which this embodiment is applied.

The rotary inertia mass damper of the third embodiment is the rotary inertia mass damper of the second embodiment with an orifice. Since the configuration other than this is the same as the configuration of the second embodiment described above, the same reference numerals as in the second embodiment are used in Figure 4 and detailed description is omitted.

The bypass line 34 is composed of a bypass line 34a that connects the drain circuit 33 to the working flow path 31a, and a bypass line 34b that connects the drain circuit 33 to the working flow path 31b. The bypass line 34 connects the working flow paths 31a and 31b. In addition, an accumulator 70 is provided in the drain circuit 33.

The bypass pipes 34a and 34b are provided with orifices 90a and 90b, respectively. The inner diameter of the orifice 90 is configured to be smaller than the inner diameter of the operating flow path 31. Since the orifice has a function of reducing pressure by adjusting the flow rate of the fluid, when the operating flow path 31 becomes high pressure, the orifice 90 can reduce the pressure. The reduced pressure viscous fluid 21 can be made to flow to the drain circuit 33 and temporarily held in the accumulator 70. By providing the orifices 90a and 90b, even if the internal pressure of the operating flow path 31 rises, the orifice can be made to reduce the pressure and flow to the drain circuit 33. This allows the reduced pressure viscous fluid 21 to be collected by the accumulator 70. Therefore, it is possible to prevent the high pressure viscous fluid 21 from flowing to the accumulator 70. The viscous fluid 21 held in the accumulator 70 is made to flow to the pressure chamber 22b via the check valve 32b. Therefore, even if the pressure inside the operating flow path suddenly increases, the pressure of the viscous fluid 21 can be reduced by the orifice and maintained by the accumulator, making it possible to control the pressure in the entire operating flow path.

According to the third embodiment of the rotary inertia mass damper configured as described above, when the entire damper becomes excessively high pressure, the viscous fluid 21 can be depressurized by the orifice 90, and the depressurized viscous fluid 21 can be stored and held in the accumulator 70. The held viscous fluid 21 can then flow to the low pressure side pressure chamber via the check valve 32. Therefore, even if the operating flow path 31 suddenly becomes high pressure, the high pressure viscous fluid 21 will not flow directly to the accumulator 70. Therefore, since the accumulator 70 is configured so that the high pressure viscous fluid 21 in the operating flow path 31 does not flow, it is possible to prevent the accumulator 70 from breaking down. In addition, since the pressure of the entire damper can be controlled by the accumulator 70, the orifice 90, and the check valve 32, it is possible to appropriately exert the damping performance as originally designed and to safely exert the damping effect of vibration acting on a building, etc.

Reference Signs List 1: Rotational inertia mass damper, 2: Damper body, 5: Movable rod, 20: Cylinder, 21: Viscous fluid, 22: Pressure chamber, 30: Hydraulic motor, 31: Working flow path, 33: Drain circuit, 51: Piston, 52: Relief valve

Claims (3)

A damper body including a cylinder filled with a viscous fluid;
a piston that divides the inside of the cylinder into a pair of pressure chambers and moves within the cylinder;
a movable rod connected to the piston and movable forward and backward relative to the cylinder;
an actuation flow path for moving the viscous fluid from the pressure chamber on a high pressure side to the pressure chamber on a low pressure side;
a hydraulic motor provided in the working flow passage and configured to convert the flow of the viscous fluid into a rotational motion;
a rotary weight to which a rotational force is applied in response to the rotational motion of the hydraulic motor;
a drain circuit for recovering the viscous fluid from the hydraulic motor;
a pair of return passages communicating with the drain circuit and connecting the high-pressure side of the working passage and the low-pressure side of the working passage via a check valve;
A rotary inertia mass damper comprising: The rotary inertia mass damper of claim 1, further comprising an accumulator in communication with the drain circuit. 3. The rotary inertia mass damper according to claim 2, further comprising a pair of bypass lines communicating with said drain circuit and connecting said high pressure side working flow passage and said low pressure side working flow passage through an orifice.

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