JP2020056448A - Eddy current type damper - Google Patents

Abstract

To provide an eddy current type damper capable of showing a high attenuation effect by an eddy current by using a small amount of permanent magnet.SOLUTION: An eddy current type damper includes: a cylinder 2; first and second pistons 3a and 3c which are slidable in first and second piston chambers 2e and 2f; a first communication path 4 which is communicated with first and second fluid chambers C1 and C2 divided by the first piston 3a; a second communication path 5 which is communicated with third and forth fluid chambers C3 and C4 divided by the second piston 3c; first and second gear motors M1 and M2 provided in the first and second communication paths 4 and 5; a first rotor 24 driven by the first gear motor M1; and a second rotor 27 driven in the opposite direction to the first rotor 24 by the second gear motor M2. One rotor 27 is configured by a conductive member, and is equipped with a plurality of permanent magnets 25 which is provided on the other rotor 24 and applies Lorentz force due to an eddy current in the opposite direction to the rotation of the rotor 27 on the rotor 27 rotating in a magnetic field.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a damper provided on a structure to suppress vibration thereof, and more particularly to an eddy current damper using eddy current generated by a permanent magnet.

  As a conventional damper of this type, for example, a damper disclosed in Patent Document 1 is known. The damper is of a ball screw type, and includes a main cylinder and a sub cylinder connected to a support member and a supported member, which are relatively displaced during an earthquake, and a screw shaft rotatably supported by the main cylinder. A ball nut that is non-rotatably supported by the sub-cylinder and is screwed to the screw shaft. Further, it includes a hysteresis material (ferromagnetic material) fixed to the outer peripheral side of the screw shaft, and a plurality of permanent magnets provided on the inner peripheral surface of the main cylinder and facing the hysteresis material.

  In this damper, when the support body and the supported body are displaced relative to each other during an earthquake or the like, the relative displacement is converted into rotational movement of the screw shaft, and the hysteresis material integrated with the screw shaft is applied to the magnetic field of the opposing permanent magnets. The vibration energy is attenuated by the hysteresis loss when rotating the, and the vibration is suppressed. Patent Document 1 discloses that a yoke material is further provided on a screw shaft, and an annular second permanent magnet facing the yoke material is further provided on an inner peripheral surface of the main cylinder. The vibration energy is further attenuated by the eddy current loss generated in the yoke material with the rotation of the screw shaft.

Japanese Patent Publication No. 5-86496

  The above-described damping effect due to the eddy current loss increases as the relative rotational speed between the yoke material and the permanent magnet increases. On the other hand, the above-mentioned conventional damper is a ball screw type in which the conversion from the linear motion (relative displacement) of the structure to the rotary motion is performed by mechanical engagement between a ball nut and a screw shaft. Since the rotation amplification ratio (rotation amount / relative displacement) is determined by the lead length of the screw shaft, the obtained relative rotation speed is limited. Therefore, in order to sufficiently obtain the above-described damping effect due to the eddy current loss, it is necessary to use a large amount of permanent magnets.

  The present invention has been made to solve the above-described problems, and a good vibration suppression effect can be obtained by exhibiting a high damping effect by eddy current while using a small amount of permanent magnets. An object is to provide an eddy current damper.

  In order to achieve this object, an invention according to claim 1 is an eddy current damper provided between a first portion and a second portion which are relatively displaced in a system including a structure, and attenuates vibration energy. A first piston chamber and a second piston chamber which are partitioned from each other in the axial direction and are filled with a working fluid; a cylinder connected to the first portion; a first piston and a second piston integrally connected to each other; A piston connected to the second part, the first and second pistons being provided in the first and second piston chambers so as to be slidable in the axial direction, respectively, Divides the first piston chamber into two fluid chambers including a first fluid chamber and a second fluid chamber, and the second piston defines the second piston chamber as a second fluid chamber including a third fluid chamber and a fourth fluid chamber. Divided into two fluid chambers, bypassing the first piston, A first communication passage communicating with the first and second fluid chambers; a second communication passage bypassing the second piston and communicating with the third and fourth fluid chambers; and a first communication passage provided in the first communication passage. A first pressure motor that converts the flow of the working fluid into a rotary motion, a second pressure motor that is provided in the second communication passage and converts the flow of the working fluid in the second communication passage into a rotary motion, A first rotor rotatably driven by a motor; and a second rotor opposed to the first rotor and rotated in a direction opposite to the first rotor by a second pressure motor. One of the rotors is made of a conductive member, and is provided on the other of the first and second rotors. The Lorentz force due to the eddy current is applied to one of the rotors rotating in the magnetic field in a direction opposite to the rotation of the one rotor. Permanent magnets configured to act Characterized in that it comprises further.

  The eddy current damper of the present invention is provided between first and second parts in a system including a structure. When vibration energy is input to the structure during an earthquake or the like and a relative displacement occurs between the first and second parts, the continuous piston moves relative to the cylinder according to the magnitude and direction of the relative displacement, The first and second pistons of the continuous piston slide in the first and second piston chambers of the cylinder, respectively.

  With the movement of the first piston, the working fluid in the first or second fluid chamber is pushed out by the first piston, flows into the first communication passage, and the flow of the working fluid in the first communication passage is changed to the first communication passage. The first rotor is rotationally driven by being converted into rotational motion by the pressure motor. Similarly, with the movement of the second piston, the working fluid in the third or fourth fluid chamber is pushed out by the second piston, flows into the second communication passage, and the flow of the working fluid in the second communication passage is The second rotor is driven to rotate by being converted into a rotating motion by the second pressure motor. As described above, the rotating inertial mass effect (inertia force) due to the rotation of the first and second rotors is exhibited, and the viscous damping effect (viscous force) due to viscous resistance when the working fluid flows through the first and second communication passages. ) Is exhibited.

  In this case, one of the first and second rotors, which is made of a conductive member, rotates in the magnetic field of a plurality of permanent magnets provided on the other rotor. As a result, an eddy current (induced current) is generated in one of the rotors, and at the same time, an interaction between the eddy current and the magnetic field of the permanent magnet generates a Lorentz force in a direction opposite to the rotation of the one rotor. By acting as a resistance force (braking force), a damping effect (damping force) due to an eddy current (Lorentz force) is exerted.

  Further, according to the eddy current damper of the present invention, since the first and second rotors are driven to rotate in opposite directions, the relative rotational speed between the permanent magnet and the conductive member increases. Thus, a high damping effect due to eddy current can be exhibited while using a small amount of permanent magnet, and a good vibration suppressing effect can be obtained.

  According to a second aspect of the present invention, there is provided an eddy current damper provided between a first portion and a second portion which are relatively displaced in a system including a structure, and attenuates vibration energy. A first piston chamber and a second piston chamber which are partitioned from each other in the axial direction and are filled with a working fluid, and a cylinder connected to the first portion, a first piston connected integrally with the first piston, and A second piston connected to the second portion, the first and second pistons being provided in the first and second piston chambers so as to be slidable in the axial direction, respectively. The one piston divides the first piston chamber into two fluid chambers including a first fluid chamber on the opposite side of the second piston chamber and a second fluid chamber on the second piston chamber side, and the second piston has a second fluid chamber. The piston chamber is connected to the third fluid chamber on the side of the first piston chamber and the first piston. A first fluid passage which is divided into two fluid chambers each comprising a ton chamber and a fourth fluid chamber on the opposite side, and which communicates with the first and third fluid chambers; and a second fluid passage which communicates with the second and fourth fluid chambers. A passage, one end communicating with at least one of the first and third fluid chambers, and the other end communicating with at least one of the second and fourth fluid chambers; The motor further includes a pressure motor that converts the flow of the working fluid in the communication path into a rotational motion, a rotor that is driven to rotate by the pressure motor, and a non-rotatable stator that faces the rotor. A plurality of permanent magnets, which are constituted by members, are provided on the other of the rotor and the stator, and are configured to apply a Lorentz force due to an eddy current to a rotor rotating in a magnetic field in a direction opposite to the rotation of the rotor. Further preparation And it features.

  The eddy current damper of the present invention is provided between the first and second parts in the system including the structure, similarly to the damper of the first aspect. When a relative displacement occurs between the first and second parts during an earthquake or the like, the first and second pistons of the continuous piston are respectively connected to the first and second cylinders of the cylinder according to the magnitude and direction of the relative displacement. It slides in the piston chamber.

  In this case, for example, when the first piston moves to the first fluid chamber side of the first piston chamber and the second piston moves to the third fluid chamber side of the second piston chamber, the operation pushed out by the first piston The fluid and the working fluid pushed out by the second piston flow into the merged communication passage from one end in a merged state. As a result, a working fluid having a flow rate that is the sum of the pushing amount by the first piston and the pushing amount by the second piston flows into the pressure motor.

  Accordingly, the speed of the pressure motor and the rotor is increased, and the relative rotation speed between the conductive member forming one of the rotor and the stator and the permanent magnet provided on the other increases. Therefore, a high damping effect due to eddy current can be exhibited while using a small amount of permanent magnet, and a good vibration suppressing effect can be obtained.

  The working fluid that has passed through the pressure motor flows out of the other end of the merging communication passage and returns to the second fluid chamber of the first piston chamber and the fourth fluid chamber of the second piston chamber. Conversely, when the first and second pistons move toward the second and fourth fluid chambers, the working fluid flows in the opposite direction, and a similar operation is obtained.

  Further, in the damper of the present invention, in addition to the damping effect (damping force) due to the eddy current described above, the rotating inertial mass effect (inertia force) due to the rotation of the rotor is exerted, and the working fluid is supplied to the first and second stations. A viscous damping effect (viscous force) due to viscous resistance when flowing through a passage or a merging communication passage is exhibited.

  According to a third aspect of the present invention, in the eddy current damper according to the second aspect, the rotor is rotatably housed in a stationary casing, and the stator is provided in the casing so as to be slidable in the axial direction. A pressure introduction passage that has three pistons, is connected in parallel with the merged communication passage at both ends, and introduces the pressure of the working fluid in the merged communication passage to the back side of the third piston; And a set spring for biasing the piston to the rear side.

  According to this configuration, the rotor is rotatably housed in the stationary casing, and the third piston as the stator is provided slidably in the axial direction in the casing, and the rotor is positioned relative to the third piston. By rotating, the damping effect by the eddy current is exhibited. Further, the pressure of the working fluid in the merged communication passage is introduced to the back side of the third piston via the pressure introduction passage. As a result, the third piston moves to a position where the pressure introduced to the rear side and the spring force of the set spring balance, and the distance between the third piston and the rotor, that is, the relative distance between the permanent magnet and the conductive member changes. This changes the eddy current damping effect.

  Since the merging communication passage communicates with the fluid chamber of the cylinder, the pressure in the merging communication passage reflects the pressure of the working fluid in the cylinder, and the pressure of the working fluid in the cylinder is changed by the axial force of the damper (acting on the damper). Axial load). Therefore, according to this configuration, the damping effect due to the eddy current can be passively variably controlled according to the pressure of the working fluid in the cylinder (the axial force of the damper).

  According to a fourth aspect of the present invention, in the eddy current damper according to the third aspect, each of the pressure introduction paths is provided at a connection portion with the junction passage, and the pressure of the working fluid in the junction passage is the first predetermined pressure. And a pair of on-off valves for opening the valve when the pressure has reached and introducing the pressure of the working fluid in the merged communication path to the pressure introduction path.

  According to this configuration, the pressure of the working fluid in the merged communication passage is reduced by the third piston because the pair of on-off valves do not open until the pressure of the working fluid in the merged communication passage reaches the first predetermined pressure. It is not introduced on the back side, and the damping effect due to the eddy current is not changed. On the other hand, when the pressure of the working fluid in the merging communication passage reaches the first predetermined pressure, the corresponding on-off valve opens. Thereby, the pressure of the working fluid is introduced to the back side of the third piston, and the third piston moves to the rotor side while compressing the set spring, so that the relative distance between the permanent magnet and the conductive member is shortened, and the vortex is reduced. The damping effect by the current increases. As described above, when the pressure of the working fluid in the merging communication passage increases to the first predetermined pressure or more, the damping effect due to the eddy current can be enhanced by opening the on-off valve.

  According to a fifth aspect of the present invention, in the eddy current damper according to the fourth aspect, the pressure introduction path has a pair of communicating portions that respectively bypass the pair of on-off valves and communicate with the merging communication passage. The apparatus further includes a pair of return valves disposed at the communication portions and opened manually to release the pressure in the pressure introduction path to the merging communication path side, thereby returning the third piston to an initial state. It is characterized by.

  After the opening / closing valve is operated as described above, the pressure on the back side of the third piston remains higher than the pressure in the merging communication passage by the spring force of the compressed set spring. According to this configuration, when the pair of return valves are manually opened after the operation of the on-off valve, the high pressure in the pressure introduction path is released to the merged communication path via the return valve. Thereby, the third piston moves by the spring force of the set spring and returns to the initial state. In this way, after the opening / closing valve operates, the third piston can be easily returned to the initial state simply by opening the pair of return valves.

  According to a sixth aspect of the present invention, in the eddy current damper according to any one of the first to fifth aspects, each of the first and second pistons operates in one of two fluid chambers defined by each piston. When the pressure of the fluid reaches the predetermined pressure, and when the pressure of the working fluid in the other of the two fluid chambers reaches the predetermined pressure, a pair of relief valves are opened to connect the two fluid chambers to each other. It is characterized by being provided.

  According to this configuration, each of the first and second pistons is provided with a pair of relief valves. These relief valves open when the pressure of the working fluid in one of the two fluid chambers defined by each piston or the pressure of the working fluid in the other reaches a predetermined pressure. Thus, the two fluid chambers communicate with each other, and the increased pressure in one fluid chamber is released to the other fluid chamber. As a result, the fluid chamber pressure is prevented from becoming excessive, and the damping force (damping force + inertia force + viscous force) of the rotary inertia mass damper reaches a plateau, so that the axial force acting on the cylinder and the piston is appropriately adjusted. Can be restricted to

It is a longitudinal section showing a damper by a 1st embodiment of the present invention. It is sectional drawing in alignment with line XX of FIG. It is a figure which shows roughly the example which applied the damper of FIG. 1 to a damping building. It is a longitudinal section showing a damper by a 2nd embodiment of the present invention. It is a longitudinal cross-sectional view which shows the 1st modification of the damper of FIG. It is a longitudinal cross-sectional view which shows the 2nd modification of the damper of FIG. It is sectional drawing which shows the 3rd modification of the damper of FIG. It is sectional drawing which shows the 4th modification of the damper of FIG.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a damper 1 according to the first embodiment. The damper 1 is of an eddy current type that exerts a damping effect by an eddy current generated by a permanent magnet, which will be described later, and includes a cylinder 2, a double piston 3 provided in the cylinder 2, and a second piston 3 connected to the cylinder 2. A first communication path 4 and a second communication path 5 are provided.

  The cylinder 2 integrally includes a cylindrical peripheral wall 2a, disk-shaped first and second end walls 2b and 2c provided at both axial ends of the peripheral wall 2a, and a central partition wall 2d. A first piston chamber 2e is defined by the peripheral wall 2a, the first end wall 2b, and the partition wall 2d, and a second piston chamber 2f is defined by the peripheral wall 2a, the second end wall 2c, and the partition wall 2d. I have. The cross-sectional areas and the axial lengths of the first and second piston chambers 2e and 2f are the same.

  The first and second piston chambers 2e and 2f and the first and second communication passages 4 and 5 are filled with a working fluid HF. The working fluid HF is composed of a working oil having an appropriate viscosity. A first fitting FL1 is provided at an end of the cylinder 2 on the first end wall 2b side via a universal joint.

  The double piston 3 is formed by integrally connecting a first piston 3a, a connecting rod 3b, a second piston 3c, and a piston rod 3d coaxially in this order. The first and second pistons 3a, 3c are housed in the first and second piston chambers 2e, 2f, respectively, and their outer peripheral surfaces are in liquid-tight contact with the inner peripheral surface of the peripheral wall 2a via a seal. . The pressure receiving areas and the axial lengths of the first and second pistons 3a and 3c are the same.

  With this configuration, the first and second pistons 3a and 3c are freely movable in the axial direction, and the first piston 3a moves the first piston chamber 2e between the first fluid chamber C1 on the first end wall 2b side and the center side. The second piston 3c divides the second piston chamber 2f into a third fluid chamber C3 on the center side and a fourth fluid chamber C4 on the second end wall 2c side. The connecting rod 3b is inserted into the center hole of the partition wall 2d and the piston rod 3d is inserted into the center hole of the second end wall 2c in a liquid-tight manner through a seal. Is provided with a second fitting FL2 via a universal joint.

  The first piston 3a is formed with a plurality of first communication holes 3e and second communication holes 3f (only one of which is shown) penetrating in the axial direction. A first relief valve 11 is provided in the first communication hole 3e, and a second relief valve 12 is provided in the second communication hole 3f.

  The first relief valve 11 is configured as a normally closed valve, has a valve body, and a spring for urging the valve body in a valve closing direction. The pressure of the working fluid HF in the second fluid chamber C2 is a set pressure. Until the predetermined pressure is reached, the first communication hole 3e is closed, and when the predetermined pressure is reached, the first communication hole 3e is opened. As a result, the pressure of the working fluid HF in the second fluid chamber C2 is released to the first fluid chamber C1 through the first communication hole 3e, and is limited to a predetermined pressure or less.

  The second relief valve 12 is configured in the same manner as the first relief valve 11, and closes the second communication hole 3f until the pressure of the working fluid HF in the first fluid chamber C1 reaches a predetermined pressure. When it reaches, the second communication hole 3f is opened. Thus, the pressure in the first fluid chamber C1 is released to the second fluid chamber C2 through the second communication hole 3f, and is limited to a predetermined pressure or less.

  Similarly, also in the second piston 3c, the first and second communication holes 3e, 3f are formed, and the first and second relief valves 11, 12 are provided, whereby the third and fourth fluid chambers are provided. The pressure of the working fluid HF in C3 and C4 is limited to a predetermined pressure or less.

  The first communication passage 4 bypasses the first piston 3a, and communicates with the first and second fluid chambers C1, C2 at both axial ends of the first piston chamber 2e. Similarly, the second communication passage 5 bypasses the second piston 3c and communicates with the third and fourth fluid chambers C3 and C4 at both axial ends of the second piston chamber 2f.

  Further, the damper 1 is connected to a first gear motor M1 provided in the first communication passage 4, a second gear motor M2 provided in the second communication passage 5, and an output shaft 23 of the first gear motor M1. A casing 24, a plurality of permanent magnets 25 housed in the casing 24, and a flywheel 27 connected to an output shaft 26 of the second gear motor M2.

  The first and second gear motors M1 and M2 convert the flow of the working fluid HF in the first and second communication passages 4 and 5 into rotational motion and output the rotational motion from the output shafts 23 and 26, respectively. (Not shown) having an inscribed or circumscribed configuration. The first and second gear motors M1 and M2 are arranged in portions of the first and second communication passages 4 and 5 close to each other. The output shafts 23 and 26 extend horizontally, are coaxially opposed to each other, and are configured to rotate in mutually opposite directions.

  The casing 24 is made of, for example, a ferromagnetic material such as a steel material, and is formed in a short cylindrical shape including a peripheral wall 24a and left and right disk-shaped end walls 24b, 24b. The output shaft 23 of the first gear motor M1 is formed. And are integrally provided coaxially. The plurality of permanent magnets 25 are provided on the inner surfaces of the left and right end walls 24b, 24b of the casing 24. As shown in FIG. 2, the permanent magnets 25 are arranged at equal intervals in the circumferential direction on the outer peripheral portion of the end wall 24b, and the directions of their magnetic poles are set so as to be alternately different between each two adjacent ones. Have been.

  The output shaft 26 of the second gear motor M2 extends into the casing 24 through the center hole of the one end wall 24b, and the flywheel 27 is coaxially and integrally connected to the inner end of the output shaft 26. ing. Since this configuration and the output shafts 23 and 26 rotate in directions opposite to each other as described above, the casing 24 and the flywheel 27 are always rotationally driven in directions opposite to each other. The flywheel 27 is made of a conductive member, for example, a steel material, and is disposed between the left and right permanent magnets 25 and faces them.

  FIG. 3 shows an example in which the damper 1 having the above configuration is applied to a damping building. In this example, a V-shaped brace BR is provided on a portal frame formed by upper and lower beams BU and BL and left and right columns PL and PR of a structure B which is a building. The damper 1 is mounted horizontally between the corners of the lower beam BL and the left column PL and the V-shaped brace BR via first and second attachments FL1 and FL2. In addition, as a method of connecting the damper 1 to the structure B, it goes without saying that another appropriate method may be adopted.

  Next, the operation of the damper 1 having the above configuration will be described. When the vibration of the structure B is not generated, the damper 1 is in the initial state shown in FIG. 1, and the first and second pistons 3a and 3c are moved in the axial direction of the first and second piston chambers 2e and 2f. It is located in the central, neutral position.

  From this initial state, when a relative displacement in the horizontal direction occurs between the upper beam BU and the lower beam BL as the structure B vibrates during an earthquake or the like, the first and second pistons 3a and 3c are provided. The connecting piston 3 moves integrally in the axial direction with a direction and a stroke corresponding to the relative displacement. Accordingly, the working fluid HF in the first and second piston chambers 2e and 2f is pushed out by the first and second pistons 3a and 3c, respectively, and flows into the first and second communication passages 4 and 5.

  For example, when the double piston 3 moves to the left in FIG. 1, the working fluid HF in the first piston chamber 2e flows into the first communication passage 4 from the first fluid chamber C1 as indicated by an arrow. Then, the working fluid HF in the second piston chamber 2f flows into the second communication passage 5 from the third fluid chamber C3. In this case, since the pressure receiving areas and the movement amounts of the first and second pistons 3a and 3c are the same, the flow rates of the working fluid HF in the first and second communication passages 4 and 5 are equal to each other.

  Then, the flow of the working fluid HF in the first communication passage 4 is converted into a rotational motion by the first gear motor M1, whereby the casing 24 is driven to rotate and the working fluid HF in the second communication passage 5 is rotated. The flywheel 27 is rotationally driven in a direction opposite to that of the casing 24 by the flow of the air being converted into rotational motion by the second gear motor M2. The rotation of the casing 24 and the flywheel 27 exerts a rotational inertial mass effect (inertial force). In addition, a viscous damping effect (viscous force) is exerted by viscous resistance when the working flow HF flows through the first and second communication passages 4 and 5.

  In addition, as the casing 24 and the flywheel 27 rotate relative to each other, the flywheel 27 formed of a conductive member rotates in the magnetic field of the plurality of permanent magnets 25 provided in the casing 24. As a result, an eddy current (induced current) is generated in the flywheel 27, and at the same time, due to the interaction between the eddy current and the magnetic field of the permanent magnet 25, a Lorentz force is generated in the flywheel 27 in a direction opposite to the rotation of the flywheel 27. By acting as a force (braking force), a damping effect (damping force) is exhibited.

  Further, according to the damper 1, the casing 24 and the flywheel 27 are rotationally driven in directions opposite to each other. Therefore, the relative rotation speed between the permanent magnet 25 provided on the casing 24 and the conductive member constituting the flywheel 27 increases. Thus, a high damping effect due to eddy current (Lorentz force) can be exhibited while using a small amount of permanent magnets, and a good vibration suppressing effect can be obtained.

  Next, a damper 31 according to a second embodiment of the present invention will be described with reference to FIG. In the figure, the same reference numerals are given to the same or equivalent components as those of the first embodiment. Compared to the damper 1 of the first embodiment, the damper 31 increases the flow rate of the working fluid HF flowing into the gear motor by using one gear motor and changing the configuration of the communication passage. The differences are. Hereinafter, description will be made focusing on portions different from the first embodiment.

  The damper 31 includes first and second communication paths 32 and 33 and a merged communication path 34, and a gear motor M is provided in the merged communication path 34. The first communication passage 32 communicates with the end of the first fluid chamber C1 of the cylinder 2 opposite to the first piston 3a and the end of the third fluid chamber C3 opposite to the second piston 3c. The second communication passage 33 communicates with an end of the second fluid chamber C2 opposite to the first piston 3a and an end of the fourth fluid chamber C4 opposite to the second piston 3c. Further, like the second communication passage 5 of the first embodiment, the merging communication passage 34 bypasses the second piston 3c, and the third and fourth fluid chambers C3 are provided at both axial ends of the second piston chamber 2f. , C4.

  The gear motor M is of an internal or external type having gears (not shown), like the first and second gear motors M1 and M2 of the first embodiment. The gear motor M is arranged at the center of the merged communication passage 34, converts the flow of the working fluid HF in the merged communication passage 34 into a rotational motion, and outputs the rotational motion from the output shaft 26. The output shaft 26 extends vertically downward from the main body of the gear motor M, and a flywheel 27 made of a conductive member is coaxially and integrally connected to the lower end of the output shaft 26. The flywheel 27 is rotatably accommodated in the casing 24.

  The casing 24 is made of a ferromagnetic material such as a steel material, and is formed in a short cylindrical shape including a peripheral wall 24a and upper and lower disc-shaped end walls 24b, 24b. It is fixed to 2.

  The plurality of permanent magnets 25 are provided on the inner surfaces of the upper and lower end walls 24b, 24b of the casing 24. Although not shown, they are arranged at equal intervals in the circumferential direction on the outer peripheral portion of the end wall 24b. The directions of the magnetic poles are set so as to be alternately different between each two adjacent ones.

  Next, the operation of the damper 31 having the above configuration will be described. When the vibration of the structure B is not generated, the damper 31 is in the initial state shown in FIG. 4, and the first and second pistons 3a and 3c are the centers of the first and second piston chambers 2e and 2f. It is located in a neutral position.

  From this initial state, when a horizontal relative displacement occurs between the upper beam BU and the lower beam BL due to the vibration of the structure B during an earthquake or the like, a double piston having first and second pistons 3a and 3c 3 move integrally in the axial direction according to the relative displacement. Thereby, for example, when the dual piston 3 moves to the left in FIG. 4, the working fluid HF in the first and second piston chambers 2e and 2f is reduced to the first and second By the pistons 3a and 3c, they are pushed to the left at the same flow rate as each other.

  In this case, the working fluid HF pushed out by the first piston 3a flows from the first fluid chamber C1 through the first communication passage 32 into the third fluid chamber C3 of the second piston chamber 2f, and the second piston 3c After joining with the working fluid HF extruded in the above, the fluid flows into the joining communication passage 34. As a result, the working fluid HF having a flow rate that is the sum of the pushing amount by the first piston 3a and the pushing amount by the second piston 3c flows into the gear motor M, so that the speed of the gear motor M is increased.

  More specifically, in this example, since the pressure receiving areas and the movement amounts of the first and second pistons 3a and 3c are equal to each other, the pushing amounts of the working fluid HF by the two pistons 3a and 3c are also equal to each other. Therefore, assuming that each extrusion amount is Qf, the flow rate flowing into the gear motor M is 2Qf which is twice as large. Further, since the rotation amount of the gear motor M is proportional to the flow rate of the working fluid HF flowing therein, the speed of the gear motor M is doubled. The working fluid HF having a flow rate of 2Qf that has passed through the gear motor M is returned to the fourth fluid chamber C4, and the working fluid HF corresponding to the flow rate Qf flows into the second fluid chamber C2 via the second communication passage 33.

  Further, as described above, the speed of the gear motor M is increased, and the speed of the flywheel 27 integrated therewith is increased. As a result, the relative rotational speed with the permanent magnet 25 provided on the casing 24 increases. Therefore, similarly to the first embodiment, a high damping effect due to eddy current (Lorentz force) can be exhibited while using a small amount of permanent magnet, and a good vibration suppressing effect can be obtained.

  Next, a damper 41 according to a first modification of the second embodiment will be described with reference to FIG. In the figure, the same reference numerals are given to the same or equivalent components as the second embodiment in FIG. This damper 41 is obtained by adding a variable damping mechanism 42 for making the damping effect by the eddy current variable to the damper 31 of the second embodiment.

  In the damper 41, the merging communication path 34 is disposed at a position relatively close to the cylinder 2, and a gear motor M is provided in the merging communication path 34. An output shaft 26 of the gear motor M extends vertically upward, and a flywheel 27 formed of a conductive member is coaxially and integrally connected to an upper end thereof. The flywheel 27 is housed in the casing 24.

  In the casing 24, movable plates 43, 43 are provided above and below the flywheel 27. Each movable plate 43 is formed of a disk made of a ferromagnetic material such as a steel material, and a plurality of permanent magnets 25 are arranged on the inner surface thereof as in the second embodiment. The movable plates 43, 43 are slidably and vertically slidable in the casing 24 in a liquid-tight manner, and bias the movable plates 43, 43 toward the initial position (outward) between them. A plurality of set springs 44 are arranged.

  Further, upper and lower pressure introduction passages 45 are provided in parallel with the junction communication passage 34. These pressure introduction passages 45 are provided in parallel with each other, communicate with both ends of the merging communication passage 34, respectively, and are passed through the rear surfaces of the upper and lower movable plates 43, 43. With the configuration described above, the pressure of the working fluid HF in the third and fourth fluid chambers C3 and C4 of the cylinder 2 is introduced to the back surfaces of the movable plates 43 and 43 via the pressure introduction passages 45 and 45. The movable plate 43, the set spring 44, and the pressure introduction path 45 constitute a variable damping mechanism 42.

  In this damper 41, the operation of the above-described damper 31 of the second embodiment can be similarly obtained. In addition, in the damper 41, the pressure of the working fluid HF in the third and fourth fluid chambers C3, C4 of the cylinder 2 is introduced to the rear side of the movable plates 43, 43 via the pressure introduction paths 45, 45. Is done. As a result, the movable plate 43 moves to a position where the pressure introduced to the rear side and the spring force of the set spring 44 are balanced, the distance between the movable plate 43 and the flywheel 27, and the permanent magnet 25 provided on the movable plate 43. And the relative distance (the size of the gap) between the conductive member and the flywheel 27 changes. Therefore, the damping effect due to the eddy current can be passively changed (variably controlled) according to the pressure of the working fluid HF.

  For example, when the pressure of the working fluid HF in the third or fourth fluid chamber C3, C4 increases, the movable plates 43, 43 move closer to the center of the casing 24, and as a result, the permanent magnet 25 and the flywheel 27 move. Is reduced, a greater eddy current damping effect can be obtained.

  Next, a damper 51 according to a second modification of the second embodiment will be described with reference to FIG. In the figure, the same reference numerals are given to the same or equivalent components as those of the second embodiment of FIG. 4 and the first modification of FIG. This damper 51 is obtained by adding a pair of open / close valves 52, 52 and a pair of return valves 53, 53 to the damper 41 of the first modified example.

  The pair of on-off valves 52, 52 are respectively disposed at connection portions of the pressure introduction passage 45 with both ends of the merging communication passage 34. Each on-off valve 52 is configured as a normally closed valve, and has a valve body that opens and closes the pressure introduction path 45 and a spring (neither is shown) that biases the valve body in the valve closing direction. The on-off valve 52 on the third fluid chamber C3 side is maintained in a closed state until the pressure of the working fluid HF in the third fluid chamber C3 reaches a first predetermined pressure which is a set pressure, and reaches the first predetermined pressure. The valve opens when it does. Similarly, the on-off valve 52 on the fourth fluid chamber C4 side is maintained in a closed state until the pressure of the working fluid HF in the fourth fluid chamber C4 reaches the first predetermined pressure, and has reached the first predetermined pressure. Sometimes open.

  When the on-off valve 52 is opened as described above, the pressure of the working fluid HF in the third or fourth fluid chambers C3 and C4 is introduced to the back side of the movable plate 43 via the on-off valve 52 and the pressure introduction path 45. When the movable plate 43 moves while compressing the set spring 44, the relative distance between the permanent magnet 25 and the conductive member is shortened, and the damping effect due to the eddy current is increased. As described above, when the pressure of the working fluid HF in the third or fourth fluid chamber C3, C4 increases to the first predetermined pressure or more, the opening / closing valve 52 opens to enhance the damping effect due to the eddy current. can do.

  The pair of return valves 53, 53 is for returning the movable plates 43, 43 operated during an earthquake or the like to an initial state, and is provided in a communication portion 52 a that bypasses each on-off valve 52. Each return valve 53 is, for example, a screw type that is manually operated, and is configured to close the communication part 52a when the screw is tightened and to open the communication part 52a when the screw is loosened. ing.

  After the opening / closing valve 52 operates as described above, the pressure in the pressure introduction passage 45 is increased by the pressure of the compressed set spring 44 by the pressure in the third or fourth fluid chamber C3, C4. It remains at a higher level. Therefore, when the return valves 53, 53 are manually opened after the operation of the on-off valve 52, the high pressure in the pressure introduction path 45 is increased via the return valves 53, 53 to the third and fourth fluid chambers C3, Each escapes to the C4 side. Thereby, the movable plates 43 return to the initial position by the urging force of the set spring 44. Thus, the movable plate 43 can be easily returned to the initial state only by opening the return valve 53.

  Note that the present invention can be implemented in various modes without being limited to the above-described embodiments and modified examples. First, in the embodiment, a gear motor is used as the pressure motor. However, as long as the flow of the working fluid HF in the communication passage can be converted into a rotational motion, another type of pressure motor, such as a piston motor, is used. Of course, a vane motor, a screw motor, or the like may be used. Further, the number and arrangement of the plurality of permanent magnets 25 can be appropriately increased, decreased, and changed in addition to those described in the embodiment.

  In the first and second embodiments, the casing 24 is composed of a ferromagnetic material + a plurality of permanent magnets 25, and the flywheel 27 is composed of a conductive member. The flywheel 27 may be composed of a ferromagnetic material and a plurality of permanent magnets 25.

  Further, in the first and second embodiments, the plurality of permanent magnets 25 are provided in two rows on each of the end walls 24b, 24b of the casing 24, but are provided in one row only on one end wall 24b. Is also good. Further, in the first and second modifications, the movable plates 43 are arranged above and below the flywheel 27. However, only one of them may be movable and the other may be fixed.

  Further, in the second embodiment, the merging communication passage 34 communicates with the third and fourth fluid chambers C3 and C4 of the cylinder 2, but as shown in FIG. 7, the first and fourth fluid chambers C1 and C4, It may be connected to C4, or may be connected to the first and second fluid chambers C1, C2 and the second and third fluid chambers C2, C3 (not shown). Alternatively, as shown in FIG. 8, one end and the other end of the merging communication path 34 may communicate with the first and second communication paths 32 and 33, respectively.

  Furthermore, in the second embodiment, the continuous piston is the double piston 3 having the first and second pistons 3a and 3c, but the number of pistons may be three or more. Further, in the above-described embodiments, the cross-sectional areas of the first and second piston chambers 2e and 2f and the pressure receiving areas of the first and second pistons 3a and 3c are set to be the same. It is needless to say that may be different.

  Further, the embodiment is an example in which the damper 1 and the like are used as a vibration control device for the structure B, but may be used as a seismic isolation device. In addition, the detailed configuration of the damper can be appropriately changed within the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Damper of 1st Embodiment 2 Cylinder 2e 1st piston chamber 2f 2nd piston chamber 3 2 piston (continuous piston)
3a 1st piston 3c 2nd piston 4 1st communication path 5 2nd communication path 11 1st relief valve (relief valve)
12 Second relief valve (relief valve)
31 Damper of the second embodiment 32 First communication path 33 Second communication path 34 Merging communication path 41 Damper of first modification 43 Movable plate (third piston)
44 Set spring 45 Pressure introduction path 51 Damper of second modification 52 Open / close valve 53 Return valve B Structure HF Working fluid C1 First fluid chamber C2 Second fluid chamber C3 Third fluid chamber C4 Fourth fluid chamber M1 First gear Motor (first pressure motor)
M2 2nd gear motor (2nd pressure motor)
M gear motor (pressure motor)

Claims (6)

An eddy current damper provided between a first portion and a second portion that are relatively displaced in a system including a structure, and attenuates vibration energy,
A cylinder having a first piston chamber and a second piston chamber which are partitioned from each other in an axial direction and are filled with a working fluid, and which are connected to the first portion;
A first piston and a second piston integrally connected to each other, and a continuous piston connected to the second portion;
The first and second pistons are slidably provided in the first and second piston chambers in the axial direction, respectively, and the first piston divides the first piston chamber into a first fluid chamber and a second fluid chamber. And the second piston partitions the second piston chamber into two fluid chambers including a third fluid chamber and a fourth fluid chamber.
A first communication passage that bypasses the first piston and communicates with the first and second fluid chambers;
A second communication passage that bypasses the second piston and communicates with the third and fourth fluid chambers;
A first pressure motor that is provided in the first communication path and converts a flow of the working fluid in the first communication path into a rotational motion;
A second pressure motor that is provided in the second communication path and converts a flow of the working fluid in the second communication path into a rotational motion;
A first rotor rotationally driven by the first pressure motor;
A second rotor opposed to the first rotor and driven to rotate in a direction opposite to the first rotor by the second pressure motor;
One of the first and second rotors is formed of a conductive member,
A plurality of rotors provided on the other of the first and second rotors and configured to apply Lorentz force due to eddy current to the one rotor rotating in a magnetic field in a direction opposite to the rotation of the one rotor. An eddy current damper, further comprising a permanent magnet. An eddy current damper provided between a first portion and a second portion that are relatively displaced in a system including a structure, and attenuates vibration energy,
A cylinder having a first piston chamber and a second piston chamber which are partitioned from each other in an axial direction and are filled with a working fluid, and which are connected to the first portion;
A first piston and a second piston integrally connected to each other, and a continuous piston connected to the second portion;
The first and second pistons are slidably provided in the first and second piston chambers in the axial direction, respectively, and the first piston connects the first piston chamber to a side opposite to the second piston chamber. The first and second piston chambers are divided into two fluid chambers each including a first fluid chamber and a second fluid chamber on the second piston chamber side, and the second piston is configured to divide the second piston chamber into a third fluid chamber on the first piston chamber side. And a second fluid chamber consisting of the first piston chamber and a fourth fluid chamber on the opposite side,
A first communication passage communicating with the first and third fluid chambers;
A second communication passage communicating with the second and fourth fluid chambers;
A merging communication passage having one end communicating with at least one of the first and third fluid chambers and the other end communicating with at least one of the second and fourth fluid chambers;
A pressure motor that is provided in the merged communication path and converts the flow of the working fluid in the merged communication path into rotational motion;
A rotor rotationally driven by the pressure motor,
A non-rotatable stator facing the rotor,
One of the rotor and the stator is formed of a conductive member,
The apparatus further includes a plurality of permanent magnets provided on the other of the rotor and the stator and configured to apply a Lorentz force due to an eddy current to the rotor rotating in a magnetic field in a direction opposite to the rotation of the rotor. An eddy current damper characterized by the following. The rotor is rotatably housed in a stationary casing,
The stator has a third piston slidably provided in the casing in the axial direction,
A pressure introduction path that is connected in parallel with the merged communication path at both ends and that introduces the pressure of the working fluid in the merged communication path to the back side of the third piston;
The eddy current damper according to claim 2, further comprising: a set spring provided in the casing and for urging the third piston toward a rear side.   Each of the pressure introduction passages is provided at a connection portion with the merged communication passage, and opens when the pressure of the working fluid in the merged communication passage reaches a first predetermined pressure, and the working fluid in the merged communication passage is 4. The eddy current damper according to claim 3, further comprising a pair of on-off valves for introducing the pressure into the pressure introduction path. The pressure introduction path has a pair of communicating portions that respectively bypass the pair of on-off valves and communicate with the merging communication passage,
Each of the pair of communication portions is arranged at the communication portion, and is manually opened to release the pressure in the pressure introduction passage to the merging communication passage side, thereby returning the third piston to an initial state. The eddy current damper according to claim 4, further comprising a return valve.   Each of the first and second pistons is provided when the pressure of the working fluid in one of the two fluid chambers defined by the piston reaches a predetermined pressure, and when the pressure of the working fluid in the other of the two fluid chambers increases. The eddy current according to any one of claims 1 to 5, further comprising a pair of relief valves that open when the pressure reaches a predetermined pressure and connect the two fluid chambers to each other. Formula damper.

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