JP2023139990A - Rotational inertia mass damper - Google Patents

Abstract

To provide a rotational inertia mass damper which has a pressure motor, and can be compactly used as a seismic isolator by shortening a length in an axial line direction.SOLUTION: A mass damper 1 comprises: an inner cylinder 2 which is filled with a working fluid HF; an outer cylinder 9 for defining a tank chamber 12 between the inner cylinder 2 and itself; a piston 3 slidably arranged in the inner cylinder 2, and partitioning a first oil chamber 2e at a first end wall 2b side and a second oil chamber 2f at a second end wall 2c side; a piston rod 10 extending to the first oil chamber 2e side from the piston 3; a communication path 4 communicating with the first and second oil chambers 2e, 2f, and penetrating the outer cylinder 9; first and second check valves 27, 25 for allowing only a flow of the working fluid HF from the tank chamber 12 to the second oil chamber 2f, and a flow in a reverse direction; a gear motor 5 for converting the circulation of the working fluid HF in the communication path 4 to a rotational motion; and a flywheel 6 driven by the gear motor 5, and exerting a rotational inertia mass effect.SELECTED DRAWING: Figure 1

Description

The present invention relates to a rotary inertial mass damper that suppresses vibrations of a structure by the rotary inertial mass effect of a rotating mass driven by a pressure motor.

The applicant has disclosed a rotary inertial mass damper of this type, for example in US Pat. This rotary inertial mass damper is installed as a vibration damping device, for example, between an upper beam and a lower beam in a structure, and includes a cylinder filled with working fluid and connected to the upper beam, and a cylinder inside the cylinder. a piston that is movable and divides the inside of the cylinder into a first fluid chamber and a second fluid chamber; It includes a piston rod that is connected to the fluid chamber, and a communication passage that bypasses the piston and communicates with the first and second fluid chambers. A gear motor is provided in the communication path, and a rotating mass is connected to the gear motor.

In this rotary inertial mass damper, when the upper and lower beams of the structure are displaced relative to each other during an earthquake or the like, the relative displacement is transmitted to the cylinder and the piston, causing the piston to reciprocate with respect to the cylinder. Accordingly, the working fluid in one of the first and second fluid chambers is pushed out by the piston, flows through the communication path, and flows into the gear motor. Accordingly, the flow of the working fluid is converted into rotational motion by the gear motor and transmitted to the rotating mass, thereby exerting a rotational inertial mass effect by the rotating mass. Further, due to viscous resistance when the working fluid flows through the communication path, a viscous damping effect is also exhibited, thereby providing a vibration damping effect.

JP2020-94680A

When a gear motor-type rotary inertial mass damper such as the one described above is installed between a structure and the ground and used as a seismic isolation device, generally speaking, compared to when it is used as a vibration damping device within a structure, The stroke (relative displacement) of the damper becomes very large. In contrast, in the conventional rotary inertial mass damper described above, the piston rod extends on both sides of the piston, and the installation length of the damper in the axial direction is the sum of the length of the piston rod and the stroke of the damper. There is a problem in that the damper cannot be configured compactly in the axial direction, at least because it is necessary.

The present invention has been made to solve such problems, and when equipped with a pressure motor, the rotational inertia can be compactly used as a seismic isolation device by shortening the length in the axial direction. The purpose is to provide a mass damper.

In order to achieve this object, the invention according to claim 1 provides a rotary inertial mass damper that is provided between a first portion and a second portion that are relatively displaced in a system including a structure, and suppresses vibrations of the structure. an inner cylinder having a circumferential wall and first and second end walls facing each other in the axial direction and filled with a working fluid; provided so as to surround at least the circumferential wall and the second end wall of the inner cylinder; A tank chamber for storing a working fluid is defined between the peripheral wall and the second end wall, and an outer cylinder is connected to the first part, and an outer cylinder is slidably provided in the inner cylinder and extends inside the inner cylinder. a piston partitioned into a first fluid chamber on the first end wall side and a second fluid chamber on the second end wall side; a piston that is integrally provided with the piston and extends in the axial direction from the piston toward the first fluid chamber side; a piston rod that bypasses the piston, communicates with the first and second fluid chambers, extends externally through the outer cylinder, and is filled with working fluid; a first check valve that is provided on the second end wall of the inner cylinder and that allows the working fluid to flow only from the tank chamber to the second fluid chamber; a second check valve that allows only the flow of the working fluid; a pressure motor that is provided in the communication passage and converts the flow of the working fluid in the communication passage into rotational motion; and a second check valve that is connected to the pressure motor and driven by the pressure motor. A rotating mass that exhibits a rotational inertial mass effect by rotating the mass.

The rotary inertial mass damper of the present invention is of a pressure motor type having an inner cylinder, an outer cylinder, a piston, a piston rod, a communication passage, a pressure motor, and a rotating mass configured as described above, and is a structure whose vibration is to be suppressed. is provided between a first portion and a second portion that are relatively displaced within a system including a first portion and a second portion that are relatively displaced. Particularly in this rotary inertial mass damper, the piston rod extends only from the piston toward the first fluid chamber side, and the working fluid is stored in the tank chamber between the inner cylinder and the outer cylinder, and the second fluid chamber is not provided with the piston rod. First and second check valves are provided on the second end wall on the side of the fluid chamber to allow the working fluid to flow only from the tank chamber to the second fluid chamber and only in the opposite direction, respectively.

With this configuration, when vibration is input to the structure during an earthquake and a relative displacement occurs between the first and second parts, the relative displacement is transmitted to the outer cylinder and the piston rod, and the piston is moved to the inner cylinder. Slides (reciprocates) inside the cylinder. As the piston reciprocates, the working fluid in the first or second fluid chambers on both sides of the piston is pushed out by the piston and flows into the communication path provided with the pressure motor. Accordingly, the flow of the working fluid is converted into rotational motion by the pressure motor and transmitted to the rotating mass, whereby a rotational inertial mass effect by the rotating mass is exerted, thereby suppressing vibration of the structure.

Further, according to the rotary inertial mass damper of the present invention, when the piston moves toward the first fluid chamber (when the piston rod is extended), the pressure in the second fluid chamber decreases. When the stop valve opens, the working fluid flows from the tank chamber into the second fluid chamber. As a result, the second fluid chamber is replenished with the working fluid that is insufficient due to the difference in cross-sectional area between the first and second fluid chambers depending on the presence or absence of the piston rod.

Conversely, when the piston moves toward the second fluid chamber (when the piston rod contracts), the second check valve opens as the pressure in the second fluid chamber increases. As a result, the working fluid flows out from the second fluid chamber to the tank chamber. As a result, excess working fluid due to the difference in cross-sectional area between the first and second fluid chambers depending on the presence or absence of the piston rod is discharged from the second fluid chamber.

As described above, when the structure vibrates, as the piston reciprocates, the action of the first and second check valves allows the second fluid chamber to be replenished or refilled depending on the presence or absence of the piston rod. Exhaust is automatically carried out without excess or deficiency. As a result, the reciprocating movement of the piston and the flow of the working fluid in the communication path are performed smoothly, and good operation of the pressure motor is ensured, so that the rotational inertial mass effect by the rotating mass can be satisfactorily exhibited.

Furthermore, according to the rotary inertial mass damper of the present invention, the piston rod is provided only on one side of the piston and is shorter than the conventional case in which the piston rod is provided on both sides of the piston. The length in the direction can be shortened, and it can also be used compactly as a seismic isolation device.

The invention according to claim 2 is the rotary inertial mass damper according to claim 1, which is provided in the piston, opens when the pressure of the working fluid in the first fluid chamber reaches a first predetermined pressure, and a first pressure regulating valve that adjusts the pressure in the first fluid chamber by causing the working fluid in the fluid chamber to flow out into the second fluid chamber; and when the pressure of the working fluid in the second fluid chamber reaches a first predetermined pressure. The present invention is characterized in that it further includes a second pressure regulating valve that adjusts the pressure in the second fluid chamber by opening the valve and causing the working fluid in the second fluid chamber to flow out into the first fluid chamber.

According to this configuration, the first pressure regulating valve and the second pressure regulating valve are provided on the piston, and the first pressure regulating valve opens when the pressure of the working fluid in the first fluid chamber reaches the first predetermined pressure. The pressure in the first fluid chamber is adjusted by causing the working fluid in the first fluid chamber to flow out into the second fluid chamber. This suppresses an increase in the pressure within the first fluid chamber, and provides a damping force due to viscous resistance when the working fluid flows through the first pressure regulating valve. Similarly, when the pressure of the working fluid in the second fluid chamber reaches the first predetermined pressure, the valve opens and the working fluid in the second fluid chamber flows out into the first fluid chamber, thereby reducing the pressure in the second fluid chamber. Adjust. This suppresses an increase in the pressure within the second fluid chamber, and provides a damping force due to viscous resistance when the working fluid flows through the second pressure regulating valve.

Due to the actions of the first and second pressure regulating valves as described above, the first and second fluid chambers function as cushions at the initial stage of vibration, thereby alleviating the impact on the pressure motor and avoiding the adverse effects of the impact. be able to.

The invention according to claim 3 is the rotary inertial mass damper according to claim 2, wherein the damper is provided in the piston, and the pressure of the working fluid in the first fluid chamber reaches a second predetermined pressure that is higher than the first predetermined pressure. a first relief valve that opens when the pressure in the first fluid chamber is released to the second fluid chamber; and a second relief valve that opens when the pressure of the working fluid in the second fluid chamber reaches a second predetermined pressure. The fluid chamber is characterized in that it further includes a second relief valve that releases the pressure inside the fluid chamber to the first fluid chamber.

According to this configuration, the first relief valve and the second relief valve are provided in the piston. When the damping coefficient after relief is 0, the pressure in the first fluid chamber is limited to below the second predetermined pressure. be done. Similarly, the second relief valve opens when the pressure of the working fluid in the second fluid chamber reaches a second predetermined pressure, thereby allowing the working fluid to escape to the first fluid chamber. When the damping coefficient is 0, the pressure within the second fluid chamber is limited to a second predetermined pressure or less. As described above, it is possible to prevent the pressure in the first and second fluid chambers from becoming excessively high, and to appropriately limit the axial force acting on the inner cylinder and the piston and the pressure of the working fluid acting on the pressure motor.

The invention according to claim 4 is the rotary inertial mass damper according to any one of claims 1 to 3, characterized in that the communication passage liquid-tightly penetrates the outer cylinder via a seal and extends to the outside. shall be.

According to this configuration, the gap between the communication passage and the outer cylinder through which the communication passage passes is kept liquid-tight by the seal, so that the gap between the communication passage and the outer cylinder through which the communication passage passes is maintained in a liquid-tight state. It is possible to reliably prevent leakage of the working fluid in the tank chamber from the tank chamber.

1 is a sectional view showing a mass damper according to an embodiment of the present invention. FIG. 2 is a diagram schematically showing an example in which a seismic isolation device including a mass damper is installed in a structure. FIG. 3 is a diagram showing a model of an additional vibration system composed of a mass damper and a support member. FIG. 3 is a diagram showing the relationship between the speed of hydraulic oil flowing inside the piston and damping force.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. As shown in FIG. 1, the rotational inertial mass damper (hereinafter referred to as "mass damper") 1 according to the embodiment includes an inner cylinder 2 disposed horizontally, an outer cylinder 9 provided outside the inner cylinder 2, and an inner cylinder 9 disposed outside the inner cylinder 2. A piston 3 provided in the inner cylinder 2, a communication passage 4 that bypasses the piston 3 and communicates with the inner cylinder 2, a gear motor 5 as a pressure motor arranged in the communication passage 4, and a gear motor 5 connected to the gear motor 5. It is equipped with a flywheel 6 and the like.

The inner cylinder 2 integrally includes a cylindrical peripheral wall 2a, a thin plate-shaped first end wall 2b provided at both ends of the peripheral wall 2a, and a thicker block-shaped second end wall 2c. An internal space of the inner cylinder 2 is defined by these three walls 2a to 2c.

The piston 3 is slidably provided in the inner cylinder 2 in the axial direction, and divides the internal space of the inner cylinder 2 into a first oil chamber 2e on the first end wall 2b side and a first oil chamber 2e on the second end wall 2c side. It is divided into 2 oil chambers 2f. The first and second oil chambers 2e, 2f and the communication passage 4 are filled with hydraulic oil HF. The hydraulic fluid HF is a normal one having a suitable viscosity.

A piston rod 10 is integrally and concentrically provided with the piston 3. The piston rod 10 is provided only on the first oil chamber 2e side, and penetrates a first end wall 2b of the inner cylinder 2 and a first end wall 9b of the outer cylinder 9, which will be described later, via a seal 11 in a fluid-tight manner. and extends outward. A first fixture FL1 is provided at the outer end of the piston rod 10 via a universal joint (not shown).

The outer cylinder 9 surrounds the entire inner cylinder 2, and integrally includes a cylindrical peripheral wall 9a and plate-shaped first and second end walls 9b and 9c provided at both ends thereof. The end wall 9b is fixed in contact with the first end wall 2b of the inner cylinder 2. On the other hand, a space is defined between the peripheral walls 2a and 9a of the inner cylinder 2 and the outer cylinder 9 and between the second end walls 2c and 9c, and this space serves as a tank chamber 12. Hydraulic oil HF is stored in the tank chamber 12 with an air layer A remaining at the top. A second fixture FL2 is provided on the second end wall 9c of the outer cylinder 9 via a universal joint (not shown).

The communication passage 4 is gate-shaped and includes a pair of vertical passage parts 4a, 4a extending in the vertical direction, and a horizontal passage part 4b connected between the upper ends thereof. The vertical passages 4a, 4a communicate with the first and second oil chambers 2e, 2f of the inner cylinder 2 at their lower ends, and penetrate the peripheral wall 2a of the inner cylinder 2 through the seal 13 in a fluid-tight manner, It penetrates the peripheral wall 9a of the outer cylinder 9 through the seal 14 in a fluid-tight manner.

The gear motor 5 is provided in the horizontal passage section 4b of the communication passage 4. The gear motor 5 is, for example, an internal type, and includes a housing 7 that communicates with the horizontal passage 4b through two entrances and exits (not shown), a rotatable input gear that is housed in the housing 7, and that mesh with each other. It has an output gear (none of which is shown) and an output shaft 8 that is integrally provided with the output gear. Note that as the gear motor 5, an external type may be used instead of an internal type.

Furthermore, a drain passage (not shown) is provided in the housing 7 for discharging the hydraulic oil HF. One end of the drain pipe 31 is connected to this drain passage, and the other end of the drain pipe 31 is inserted into the tank chamber 12.

The flywheel 6 is attached to the output shaft 8 of the gear motor 5. The flywheel 6 is formed into a disk shape from a material having a relatively large specific gravity, such as steel, and is coaxially and integrally provided with the output shaft 8 .

On the other hand, four communication passages are formed in the piston 3, passing through the piston 3 in the axial direction and communicating with the first and second oil chambers 2e and 2f. A first pressure regulating valve 21, a first relief valve 22, a second pressure regulating valve 23, and a second relief valve 24 are provided in each of these communication passages. Each of these valves 21 to 24 is configured as a normally closed valve, and has a valve body that opens and closes a communication passage, and a spring that biases the valve body toward the valve closing side.

The first pressure regulating valve 21 opens when the pressure in the first oil chamber 2e reaches a first predetermined pressure close to the value 0, and causes the hydraulic oil HF to flow out to the second oil chamber 2f. 1. Adjust the pressure inside the oil chamber 2e. The first relief valve 22 opens when the pressure in the first oil chamber 2e reaches a second predetermined pressure (equivalent to relief load) higher than the first predetermined pressure, and supplies hydraulic oil HF to the second oil chamber 2f. When the damping coefficient after relief is 0, the pressure in the first oil chamber 2e is limited to a second predetermined pressure or less. Contrary to the above, the second pressure regulating valve 23 adjusts the pressure in the second oil chamber 2f by opening when the pressure in the second oil chamber 2f reaches the first predetermined pressure. The second relief valve 24 opens when the pressure in the second oil chamber 2f reaches a second predetermined pressure, and when the damping coefficient after relief is 0, the pressure in the second oil chamber 2f is reduced. The pressure is limited to a second predetermined pressure or less.

Furthermore, two communication passages are formed in the second end wall 2c of the inner cylinder 2, penetrating in the axial direction and communicating with the second oil chamber 2f and the tank chamber 12. A third pressure regulating valve 25 and a third relief valve 26 configured similarly to the valves 21 to 24 described above are provided in each of these communication passages.

The third pressure regulating valve 25 has the function of a second check valve that only allows the hydraulic oil HF to flow out from the second oil chamber 2f side to the tank chamber 12 side, and reduces the pressure in the second oil chamber 2f. When the pressure reaches the first predetermined pressure, the valve opens and the hydraulic oil HF flows out to the tank chamber 12 side, thereby adjusting the pressure in the second oil chamber 2f. The third relief valve 26 opens when the pressure in the second oil chamber 2f reaches a second predetermined pressure, and releases the hydraulic oil HF to the tank chamber 12 side, so that the damping coefficient after relief is 0. In this case, the pressure in the second oil chamber 2f is limited to a second predetermined pressure or less.

Furthermore, the second end wall 2c of the inner cylinder 2 is formed with two communication holes that penetrate in the axial direction, and these communication holes are opened and closed by a check valve 27. The check valve 27 is made up of valve bodies 27a, 27a that open and close the communication hole, and a spring 27b that biases the valve body 27a toward the valve closing side, thereby allowing the flow from the tank chamber 12 side to the second oil chamber 2f. Only the inflow of hydraulic oil HF to the side is allowed.

The mass damper 1 having the above configuration is provided as a seismic isolation device 51 between a structure (building) B and its foundation F together with a plurality of seismic isolation bearings 52 such as laminated rubber type, as shown in FIG. 2, for example. . Specifically, the mass damper 1 is attached to a first support member EN1 hanging from the structure B and a second support member EN2 erected from the foundation F via first and second fixtures FL1 and FL2, respectively. It is being The operation of the mass damper 1 configured and installed in this manner will be described below.

First, when the structure B is not vibrating, the mass damper 1 is in the initial state shown in FIG. From this initial state, when the foundation F vibrates during an earthquake, a relative displacement occurs between the first and second support members EN1 and EN2, and this relative displacement is transmitted to the inner cylinder 2 and the piston 3, so that the piston 3 reciprocates within the inner cylinder 2.

For example, when the piston 3 moves toward the first oil chamber 2e (when the piston rod 10 is extended), the pressure inside the first oil chamber 2e increases due to the pressure exerted by the piston 3, and When the pressure is reached, the first pressure regulating valve 21 opens, and a part of the hydraulic fluid HF pressed by the piston 3 flows out to the second oil chamber 2f side through the first pressure regulating valve 21. Further, the remaining hydraulic oil HF flows from the first oil chamber 2e into the horizontal passage part 4b via one vertical passage part 4a of the communication passage 4, flows inside the housing 7 of the gear motor 5, and then flows through the other vertical passage part 4a. It returns to the second oil chamber 2f via the vertical passage section 4a. In this case, due to the difference in cross-sectional area between the first and second oil chambers 2e and 2f depending on the presence or absence of the piston rod 10, the insufficient amount of hydraulic oil HF in the second oil chamber 2f is removed when the check valve 27 is opened. By opening the valve, the second oil chamber 2f is replenished from the tank chamber 12.

On the other hand, contrary to the above, when the piston 3 moves toward the second oil chamber 2f (when the piston rod 10 contracts), the pressure inside the second oil chamber 2f is reduced by being pressed by the piston 3. When the pressure rises and reaches the first predetermined pressure, the second pressure regulating valve 23 opens, and a part of the hydraulic fluid HF pressed by the piston 3 flows out to the first oil chamber 2e side. Further, a part of the pressed hydraulic oil HF flowed from the second oil chamber 2f into the horizontal passage part 4b via one vertical passage part 4a of the communication passage 4, and flowed inside the housing 7 of the gear motor 5. Thereafter, it returns to the first oil chamber 2e via the other vertical passage section 4a. In this case, the excess hydraulic oil HF in the second oil chamber 2f due to the difference in cross-sectional area between the first and second oil chambers 2e and 2f is transferred to the second oil chamber by opening the third pressure regulating valve 25. The oil is discharged from the oil chamber 2f to the tank chamber 12.

When the hydraulic oil HF flows in the housing 7 of the gear motor 5 as described above, the pressure of the hydraulic oil HF is converted into rotational motion of the gear motor 5, and the flywheel 6 integrated with the output shaft 8 is rotationally driven. This brings about the rotational inertial mass effect (inertial force). In addition, by exhibiting a viscous damping effect (viscous force) due to viscous resistance when the hydraulic oil HF flows through the communication path 4, it is possible to obtain a vibration suppressing effect of the structure in addition to the rotational inertial mass effect.

Further, during operation of the mass damper 1, when the pressure of the hydraulic oil HF in the first oil chamber 2e reaches the first predetermined pressure, the first pressure regulating valve 21 opens and the hydraulic oil HF is transferred to the second oil chamber 2f. By causing the pressure in the first oil chamber 2e to flow out, the pressure in the first oil chamber 2e is released and its rise is suppressed, and when the hydraulic oil HF flows through the first pressure regulating valve 21, a damping force due to viscous resistance is obtained. It will be done. Similarly, when the pressure of the hydraulic oil HF in the second oil chamber 2f reaches the first predetermined pressure, the second pressure regulating valve 23 opens and causes the hydraulic oil HF to flow out into the first oil chamber 2e. The pressure in the second oil chamber 2f is released and its rise is suppressed, and when the hydraulic oil HF flows through the second pressure regulating valve 23, a damping force due to viscous resistance is obtained. Due to the actions of the first and second pressure regulating valves 21 and 23 as described above, the first and second oil chambers 2e and 2f function as cushions at the initial stage of vibration, so that the impact on the gear motor 5 is alleviated. , the negative effects of impact are avoided.

Furthermore, when the pressure of the hydraulic oil HF in the first oil chamber 2e reaches the second predetermined pressure, the first relief valve 22 opens and the hydraulic oil HF is released to the second oil chamber 2f. When the damping coefficient after relief is 0, the pressure in the first oil chamber 2e is limited to a second predetermined pressure or less. Similarly, when the pressure of the hydraulic oil HF in the second oil chamber 2f reaches the second predetermined pressure, the second relief valve 24 opens and the hydraulic oil HF is released to the first oil chamber 2e. If the damping coefficient after relief is 0, the pressure in the second oil chamber 2f is limited to a second predetermined pressure or less. As described above, the pressure in the first and second oil chambers 2e and 2f is prevented from increasing excessively, and the axial force acting on the inner cylinder 2 and piston 3 and the pressure of the hydraulic oil HF acting on the gear motor 5 are appropriately restricted. be done.

In addition, when the gear motor 5 operates for a long time due to the response of the structure to the input of long-period earthquake motion, for example, the pressure of the hydraulic oil HF in the housing 7 increases, and the hydraulic oil flows from the drain of the gear motor 5. When HF leaks out, the hydraulic oil HF is released through the drain pipe 31 into the tank chamber 12 which is in an atmospheric state. This reliably prevents the pressure inside the housing 7 from becoming excessively high.

The additional vibration system composed of the mass damper 1 and the support members (first and second support members EN1 and EN2) described above is modeled as shown in FIG. 3. That is, (a) an inertial mass element with an equivalent mass λmd consisting of the flywheel 6 and the hydraulic oil HF, which are in a parallel relationship with each other, and (b) a damping coefficient cd consisting of the hydraulic oil HF flowing through the communication path 4 and the gear motor 5. (c) Damping consisting of hydraulic oil HF flowing through the pressure regulating valves (first and second pressure regulating valves 21, 23) before relief of the relief valves (first and second relief valves 22, 24). A viscous element with a coefficient c1, a limiting element for the relief load Fr due to the relief valve, a viscous element with a damping coefficient c2 consisting of the pressure regulating valve after relief and the hydraulic oil HF flowing through the relief valve, and (d) compression rigidity of the hydraulic oil HF. Spring elements of stiffness kb consisting of support members including , are connected in series.

In the model of FIG. 3, Fd is a damper external force acting on the mass damper 1, and Fr is a relief load of the first and second relief valves 22 and 24. xb is the displacement of the support member including the amount of compression of the hydraulic oil HF. xiHGD is the amount of piston movement when the damper external force Fd is applied, and is expressed by the following equation (1), where V is the extrusion flow rate accompanying the movement of the piston 3, and Ap is the cross-sectional area of the piston.
xiHGD = V/Ap...(1)
Moreover, xr is an apparent movement amount obtained by dividing the flow rate Vr of the hydraulic oil HF flowing in the piston 3 through the pressure regulating valve and the relief valve by the piston cross-sectional area Ap, and is expressed by the following equation (2). xd is an apparent movement amount obtained by dividing the flow rate Vd of the hydraulic oil HF flowing into the gear motor 5 through the communication path 4 by the piston cross-sectional area Ap, and is expressed by the following equation (3).
xr = Vr/Ap...(2)
xd = Vd/Ap...(3)

Since the following equation (4) holds true between V, Vr, and Vd, the following equation (5) holds from equation (4) and equations (1) to (3).
V=Vr+Vd...(4)
xiHGD=xr+xd...(5)
Further, the pressure acting on the pressure regulating valve and the relief valve installed on the piston 3 and the pressure acting on the gear motor 5 are equal to each other. ...(6)

From these relationships (5) and (6), the following equations (7) to (9) hold true.
x = xb+xiHGD = xb+xr+xd...(7)
When |vr|≦Fr/c1 (conditions before relief)
Fd = kb xb
= c1・vr
= λmd・αd+cd・vd...(8)
When |vr|>Fr/c1 (conditions after relief)
Fd = kb xb
= sgn(vr)・Fr+c2・(vr−sgn(vr)・Fr/c1)
= λmd・αd+cd・vd...(9)
Here, x: Displacement of the entire added vibration system
c1: Attenuation coefficient before relief
c2: Attenuation coefficient after relief
vr: speed of xr
vd: speed of xd
αd: acceleration of xd
λmd: equivalent mass of mass damper
cd: damping coefficient of mass damper

From the above equations (8) and (9), the apparent velocity vr calculated from the hydraulic oil HF flowing inside the piston 3 through the pressure regulating valve and relief valve, and the damping force F due to its viscous resistance (=damper reaction force) The relationship between vr and vr is expressed as shown in FIG. 4 for the range of vr≧0. That is, the damping force F exhibits bilinear characteristics with respect to the speed vr, and the damping coefficient becomes a larger damping coefficient c1 until the relief load Fr is reached due to the hydraulic fluid HF flowing only through the pressure regulating valve, and the relief load After reaching Fr, the hydraulic fluid HF flows through both the pressure regulating valve and the relief valve, resulting in a smaller damping coefficient c2.

As described above, according to the mass damper 1 of this embodiment, the piston rod 10 is provided only on one side of the piston 3, and is shorter than the conventional case in which it is provided on both sides of the piston. The length in the axial direction can be shortened, and it can be used compactly as a seismic isolation device.

In addition, when the structure B vibrates, as the piston 3 reciprocates, the operation of the check valve 27 and the third pressure regulating valve 25 causes the hydraulic fluid to flow into the second oil chamber 2f depending on the presence or absence of the piston rod 10. HF is automatically replenished or discharged without excess or deficiency. As a result, the reciprocating movement of the piston 3 and the flow of the hydraulic oil HF in the communication path 4 are performed smoothly, and good operation of the gear motor 5 is ensured, so that the rotational inertia mass effect by the rotating mass is exerted well. be able to.

Further, when the pressure of the hydraulic oil HF in the first oil chamber 2e or the second oil chamber 2f reaches a first predetermined pressure, the first or second pressure regulating valve 21 or 23 provided on the piston 3 is opened. valve, and the hydraulic oil HF is caused to flow out to the second oil chamber 2f or the first oil chamber 2e on the opposite side. This suppresses the rise in pressure in the first oil chamber 2e or the second oil chamber 2f, and also suppresses the increase in pressure due to viscous resistance when the hydraulic oil HF flows through the first or second pressure regulating valves 21 and 23. Damping force can be obtained. As a result of the above action, the first and second oil chambers 2e and 2f function as a cushion at the initial stage of vibration, thereby alleviating the impact on the gear motor 5 and avoiding the adverse effects of the impact.

Further, when the pressure of the hydraulic oil HF in the first oil chamber 2e or the second oil chamber 2f reaches a second predetermined pressure that is higher than the first predetermined pressure, The relief valves 22 and 24 open to release the hydraulic oil HF to the second oil chamber 2f or the first oil chamber 2e on the opposite side. As a result, if the damping coefficient c2 is 0 after reaching the relief load Fr, the pressure of the hydraulic oil HF in the first oil chamber 2e or the second oil chamber 2f is limited to a second predetermined pressure or less. Therefore, it is possible to prevent the pressure from becoming excessive and to appropriately limit the axial force acting on the inner cylinder 2 and the piston 3 and the pressure of the hydraulic oil HF acting on the gear motor 5.

Furthermore, seals 14 are provided in the gaps between the vertical passages 4a, 4a of the communication passage 4 and the outer cylinder 9 through which they pass, and a liquid-tight state is maintained, so that when the mass damper 1 is installed, operated, and transported. It is possible to reliably prevent leakage of the hydraulic oil HF in the tank chamber 12 from this gap.

Note that the present invention is not limited to the described embodiments, and can be implemented in various ways. For example, in the embodiment, the second end wall 2c of the inner cylinder 2 is provided with the third pressure regulating valve 25 and the third relief valve 26, which also serve as the second check valve. may be omitted, and only the second check valve that only allows the hydraulic oil HF to flow from the second oil chamber 2f side to the tank chamber 12 side may be provided.

Furthermore, in the embodiment, the piston 3 is provided with first and second pressure regulating valves 21 and 23 and first and second relief valves 22 and 24, but one or both of these pressure regulating valves and relief valves may be Mass dampers that may be omitted and are so configured are also within the scope of the invention.

Further, although a gear motor is used as the pressure motor of the mass damper 1, other types of pressure motors may be used as long as they convert the flow of working fluid into rotational motion, such as a piston motor, a vane motor, A screw motor may also be used. Further, in the embodiment, it has been explained that normal hydraulic oil is used as the working fluid of the damper, but it goes without saying that other suitable working fluids may be used.

Further, in the embodiment, the mass damper 1 has been described as being used as a seismic isolation device, but the mass damper 1 is not limited to this, and of course may be used as a vibration damping device. In addition, it is possible to change the detailed structure as appropriate within the scope of the spirit of the present invention.

1 Mass damper (rotational inertia mass damper)
2 Inner cylinder 2a Peripheral wall of the inner cylinder 2b First end wall of the inner cylinder 2c Second end wall of the inner cylinder 2e First oil chamber (first fluid chamber)
2f 2nd oil chamber (2nd fluid chamber)
3 Piston 4 Communication path 5 Gear motor (pressure motor)
6 Flywheel (rotating body)
9 Outer cylinder 10 Piston rod 12 Tank chamber 14 Seal 21 First pressure regulating valve 22 First relief valve 23 Second pressure regulating valve 24 Second relief valve 25 Third pressure regulating valve (second check valve)
27 Check valve (first check valve)
HF hydraulic oil (working fluid)
B Structure F Foundation

Claims (4)

A rotary inertial mass damper that is provided between a first portion and a second portion that are relatively displaced in a system including a structure, and suppresses vibrations of the structure,
an inner cylinder having a peripheral wall and first and second end walls facing each other in the axial direction and filled with a working fluid;
A tank chamber is provided to surround at least the peripheral wall and the second end wall of the inner cylinder, and defines a tank chamber for storing a working fluid between the peripheral wall and the second end wall, and A connected outer cylinder,
a piston that is slidably provided in the inner cylinder and partitions the inner cylinder into a first fluid chamber on the first end wall side and a second fluid chamber on the second end wall side;
a piston rod that is integrally provided with the piston, extends in the axial direction from the piston toward the first fluid chamber, extends outside through the first end wall, and is connected to the second portion;
a communication passage that bypasses the piston, communicates with the first and second fluid chambers, extends outside through the outer cylinder, and is filled with working fluid;
a first check valve provided on the second end wall of the inner cylinder and allowing only the flow of working fluid from the tank chamber to the second fluid chamber; a second check valve that allows only the flow of working fluid;
a pressure motor that is provided in the communication path and converts the flow of working fluid in the communication path into rotational motion;
A rotary inertial mass damper comprising: a rotating mass that is connected to the pressure motor and driven by the pressure motor to exhibit a rotary inertial mass effect. A valve is provided in the piston and opens when the pressure of the working fluid in the first fluid chamber reaches a first predetermined pressure, and causes the working fluid in the first fluid chamber to flow out to the second fluid chamber. a first pressure regulating valve that adjusts the pressure in the first fluid chamber; and a first pressure regulating valve that opens when the pressure of the working fluid in the second fluid chamber reaches the first predetermined pressure, and controls the working fluid in the second fluid chamber. The rotary inertial mass damper according to claim 1, further comprising a second pressure regulating valve that adjusts the pressure in the second fluid chamber by causing the fluid to flow into the first fluid chamber. The valve is provided in the piston and opens when the pressure of the working fluid in the first fluid chamber reaches a second predetermined pressure greater than the first predetermined pressure, and the pressure in the first fluid chamber is reduced to the second predetermined pressure. a first relief valve that releases the pressure in the second fluid chamber to the first fluid chamber; and a first relief valve that opens when the pressure of the working fluid in the second fluid chamber reaches a second predetermined pressure and releases the pressure in the second fluid chamber to the first fluid chamber. 3. The rotary inertial mass damper of claim 2, further comprising: 2 relief valves. The rotary inertial mass damper according to any one of claims 1 to 3, wherein the communication passage liquid-tightly penetrates the outer cylinder via a seal and extends to the outside.

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