JP2012184816A - Damping device and vibration control device of structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a miniaturized damping device by which acting vibration can be attenuated by the inertial moment by a flywheel and resistant force adjustable by magnetorheological fluid and the magnetorheological fluid exhibits a function even without supplying vibration for stirring the magnetorheological fluid.SOLUTION: The damping device 1 a has a casing 30 formed of the first cylinder 10 and the second cylinder 20. A sleeve 40 capable of going forward and rearward is arranged in the first cylinder 10, a ball nut 42 is attached to the sleeve 40, the forward and rearward moving in the sleeve 40 is converted to a rotational movement by the ball screw 43, and the flywheel 50 in the second cylinder 20 is rotated. A sealed area 46 is formed between the flywheel 50 and the inner surface of the second cylinder 20, and the magnetorheological fluid 49 is sealed within the same. A magnetic field forming means 60 forming a magnetic field M whose strength can be adjusted crossing the sealed area 46 making the flywheel 50 as a part of the magnetic circuit is arranged in the inner periphery of the second cylinder 20.

Description

  The present invention relates to a damping device and a structure damping device. More specifically, the present invention relates to a moment of inertia of a flywheel that is rotated by a ball screw and a ball nut that converts linear motion into rotational motion, and viscosity resistance of a magnetorheological fluid. The present invention relates to a damping device used and a structure damping device using the same.

As a device for suppressing vibration transmission in a building structure or various mechanical devices, a vibration damping device using the inertia of an object has been proposed. As such a vibration damping device, there is a device that uses a mechanism that converts linear motion into rotational motion of a flywheel in order to reduce the size, and uses the inertia moment of the rotating flywheel for vibration damping.
In Patent Document 1 and Patent Document 2, a ball screw and a ball nut are used to convert a linear motion into a rotational motion to rotate a flywheel disposed in the case, and between the flywheel and the case. In which a viscous material such as synthetic rubber is disposed is described (see paragraph 0060, FIG. 6).
According to such a vibration damping device, a combination of a ball screw and a ball nut amplifies a minute translational motion and rotates the flywheel at high speed, and the inertial moment of the flywheel, the flywheel and the case, The viscous resistance between the two can be used for damping.

Further, as a vibration damping device, a device using the viscosity or friction of a magnetorheological fluid (MR fluid) for vibration damping has been proposed. Patent Document 3 describes a vibration damping device using a magnetorheological fluid. FIG. 12 is a cross-sectional view showing a schematic configuration of a conventional vibration damping device. The vibration damping device 210 includes a cylinder 212 filled with the magnetorheological fluid 211, a piston rod 213 that is inserted into the cylinder 212 and supported so as to be movable back and forth in the axial direction, and a cylinder 212 that is fixed at an appropriate position in the middle of the piston rod 213. A piston 214 for partitioning the inside, a bypass pipe 215 provided at a lower portion of the cylinder 212, and a magnetic field forming means 216 such as an electromagnet arranged along the axial direction of the bypass pipe 215 are provided. Attachment portions 212a and 213a are respectively provided at the end portion of the cylinder 212 and the end portion of the piston rod 213, and each attachment portion is attached to a different part of a building, for example.
When the building vibrates due to an earthquake or the like, the piston 214 moves in the cylinder in the axial direction to urge the magnetorheological fluid 211, and the magnetorheological fluid flows in the bypass pipe 215. At this time, the magnetic particles of the magnetorheological fluid 211 receive a magnetic field from the magnetic field generating means 216 and are connected in a chain shape, thereby causing resistance to the flow of the magnetorheological fluid 211 and damping the vibration.
According to such a vibration damping device 210, the damping characteristic by the magnetorheological fluid 211 can be adjusted and the vibration damping characteristic of the vibration damping device 210 can be changed by controlling the current to the electromagnet that is the magnetic field forming means. it can.

JP 2005-180492 A JP 2002-168283 A Japanese Patent Laid-Open No. 10-184757

However, the above-described vibration damping devices described in Patent Document 1 and Patent Document 2 suppress the transmission of the vibration force from the vibration source and the resonance amplitude by the rotational moment and the viscous resistance, and accelerate the attenuation of the generated vibration. However, the attenuation characteristic is constant. For this reason, it is difficult for such a damping device to exhibit effective damping characteristics flexibly corresponding to earthquakes having various vibration characteristics and behaviors of complex structures.
In addition, the vibration damping device described in Patent Document 3 is large in size and requires a large amount of magnetorheological fluid to fill the cylinder, resulting in high cost. Furthermore, in a vibration damping device using a magnetorheological fluid, the magnetic particles mixed in the base oil of the magnetorheological fluid precipitate if not used for a long period of time. is there. However, in the vibration damping device described in Patent Document 3, the flow of the magnetorheological fluid is small to the extent that minute vibrations are applied, so that the magnetorheological fluid is difficult to stir and the magnetic particles are likely to precipitate. For this reason, even if it tries to operate from the state where magnetic substance particles settled, there is a problem that magnetorheological fluid does not exhibit predetermined performance. This problem is remarkable when the vibration is applied to the building structure because the vibration constantly applied to the building structure is very small, and it cannot cope with a sudden earthquake.

Under such circumstances, there is a demand for a vibration damping device that is small in size and capable of adjusting vibration damping characteristics in order to perform vibration damping of a building structure. As such a vibration damping device, it is conceivable to apply a magnetorheological fluid to the vibration damping device using the above-described flywheel. However, even if these are simply combined, a sufficient vibration damping effect cannot be exhibited. The problem is how to arrange the magnetic fluid and the magnetic field forming means.
The present invention has been made in view of the above problems, and is compact and capable of attenuating the applied vibration by the inertial moment of the flywheel and the adjustable resistance force by the magnetorheological fluid. An object of the present invention is to provide a damping device in which a magnetorheological fluid can perform its function without giving vibrations.

  In order to solve the above-mentioned problems, the invention of claim 1 includes a first cylinder having an axial through-hole having a tip opening at the tip and a communication opening at the other end, and the communication opening. A casing having a hollow second cylinder fixed to the other end of the first cylinder in the same axial center and closed at the other end with the opening at one end communicating with the first cylinder; A hollow sleeve that fits into the opening of the tip of the cylinder and is supported in the axial through hole so as not to rotate and to advance and retract in the axial direction; a ball nut fixed in the sleeve; and A fly screw which is formed of a ferromagnetic material and is made of a ferromagnetic material and is rotatably arranged in the hollow inside of the second cylinder, and is connected to the ball screw and is driven to rotate. Wheel and said second A seal member that forms a sealed region in a gap between the inner wall of the cylinder and the outer periphery of the flywheel; and a magnetic field that is disposed on the inner wall of the second cylinder and that forms a magnetic field across the sealed region using the flywheel as a part of a magnetic circuit. A damping device comprising: a forming unit; and a magnetorheological fluid sealed in the sealed region.

  According to a second aspect of the present invention, there is provided a first cylinder having an axial through hole having a tip opening at the tip and a communication opening at the other end, and an opening at one end connected to the communication opening. A casing having a hollow second cylinder fixed in the same axial center to the other end of the first cylinder and closed at the other end, and in the tip opening of the first cylinder A hollow sleeve that is fitted and supported in the axial through hole so as not to rotate and to be able to advance and retreat in the axial direction, a ball screw fixed in the sleeve, and a ball screwed into a male screw portion of the ball screw A nut, a flywheel formed of a ferromagnetic material, rotatably disposed inside the hollow of the second cylinder, and connected to the ball nut and driven to rotate; and the second cylinder Inner wall and said hula A sealing member that forms a sealed region in a gap between the outer periphery of the wheel, a magnetic field forming unit that is disposed on an inner wall of the second cylinder and that forms a magnetic field across the sealed region using the flywheel as a part of a magnetic circuit, and the sealing And a magnetorheological fluid sealed in the region.

According to the damping device of the first and second aspects, the linear motion of the sleeve caused by the vibration is converted into the rotational motion by the ball nut and the ball screw, and the flywheel is rotated at high speed. In addition, the magnetic viscous fluid disposed in the sealed region between the outer periphery of the flywheel and the inner wall of the second cylinder is viscous due to the magnetic field formed by the magnetic field forming means so that the flywheel crosses the sealed region as part of the magnetic circuit. Is provided. For this reason, the damping device attenuates the vibration by the inertial moment of the flywheel and the viscous resistance applied to the flywheel by the magnetic viscous fluid.
At this time, the resistance by the magnetorheological fluid can be adjusted by adjusting the magnitude of the magnetic field by the magnetic field forming means. The magnetic field is formed by using a flywheel, which is a ferromagnetic material, as part of the magnetic circuit, and crosses the sealed region. For this reason, the magnetic fluid of the magnetorheological fluid in the sealed region is connected in a chain form between the flywheel and the second cylinder, and this chain-like magnetic fluid is subjected to shearing by the rotation of the flywheel to the flywheel. Gives viscous resistance.
In addition, since the magnetic viscous fluid is enclosed in a small volume of the sealed region between the second cylinder and the flywheel, only a small amount is required. Further, the flywheel sufficiently rotates with a minute straight movement by the amplifying action at the time of conversion from the straight movement to the rotary movement by the ball screw and the ball nut, and the magnetorheological fluid is stirred. For this reason, even if it uses in the condition where only a very small vibration is always applied, it can exhibit the damping action with respect to sudden excitation.

The invention of claim 3 is characterized in that the other end portion of the second cylinder and the sleeve include a connecting portion connected to an external member. ADVANTAGE OF THE INVENTION According to this invention, when arrange | positioning an attenuation | damping apparatus in a structure, the structural member which comprises a structure can be attached easily and the vibration of a structure can be aimed at.
The invention of claim 4 is characterized in that the magnetic field forming means comprises an electromagnet. According to the present invention, by controlling the current applied to the electromagnet, it is possible to adjust the viscosity of the magnetorheological fluid, thereby controlling the magnitude of the resistance force applied to the flywheel, It can be optimized for vibration characteristics and vibration control targets.

The invention of claim 5 is characterized in that the magnetic field forming means comprises a permanent magnet. According to the present invention, viscosity can be imparted to the magnetorheological fluid without requiring a power source, and the structure can be damped with a simple configuration.
The invention of claim 6 is characterized in that the magnetic field forming means comprises an electromagnet and a permanent magnet. According to the present invention, by controlling the current applied to the electromagnet, it is possible to adjust the viscosity of the magnetorheological fluid, thereby controlling the magnitude of the resistance force applied to the flywheel, It is possible to optimize the vibration characteristics and the object to be controlled, and to prevent the magnetic particles of the magnetorheological fluid from being always chained with a permanent magnet and to prevent the precipitation.

According to a seventh aspect of the present invention, in the damping device, the magnetic field forming means forms a magnetic field across the sealed region, with the second cylinder as a part of a magnetic circuit. According to the present invention, the magnetic field forming means can use the second cylinder as a part of the magnetic circuit, the number of components for forming the magnetic field can be reduced, and the structure of the magnetic field forming means can be simplified. it can.
The invention according to claim 8 is characterized in that the flywheel has an uneven portion on an outer periphery thereof. According to the present invention, since the surface area of the flywheel that contacts the magnetorheological fluid can be increased, the resistance force that the flywheel receives from the magnetorheological fluid can be increased.

The invention according to claim 9 is characterized in that the uneven portion of the flywheel is composed of an annular groove portion and a hook-like convex portion that are sequentially arranged in the axial direction of the flywheel. According to the present invention, when the concave and convex portions are formed on the flywheel, the rotating flywheel base material may be cut with a lathe or the like, so that the processing at the time of manufacturing the flywheel becomes easy.
According to a tenth aspect of the present invention, the dimension between the inner wall of the second cylinder and the outer peripheral surface of the flywheel in the sealed region is determined by the rotation of the flywheel caused by steady vibration when the damping device is used. The size is suitable for stirring so as not to precipitate the enclosed magnetorheological fluid. According to the present invention, when the damping device is arranged on the structure, the magnetorheological fluid does not always settle due to the rotation of the flywheel due to the steady vibration of the structure, and the damping device is not subject to a predetermined vibration. Performance can be demonstrated.

The invention according to claim 11 includes a damping device attached between the structural members of the structure, and a control means for adjusting the magnetic force of the magnetic field forming means of the damping device. It is. According to the present invention, by adjusting the magnetic force of the magnetic field forming means by the control means, changing the resistance force applied to the flywheel by the magnetorheological fluid, and adjusting the characteristics of the damping device, It can be optimized according to the characteristics of vibration.
The invention of claim 12 is characterized by comprising an uninterruptible power supply for supplying power to the attenuation device and the control means. ADVANTAGE OF THE INVENTION According to this invention, even if it is in the state where commercial power is not supplied, such as at the time of a power failure, the structure damping device can be operated normally.

The invention according to claim 13 includes an accelerometer arranged on the structural member of the building and detecting a vibration state of the structural member, wherein the magnetic force control means is based on the detected value of the accelerometer. It is characterized by controlling. According to the present invention, the control means controls the magnetic field forming means of the damping device so as to exert an optimum damping force for damping the vibration of the structural member detected by the accelerometer, and effectively controls the vibration of the structure. Can be attenuated.
According to a fourteenth aspect of the present invention, the accelerometer is arranged corresponding to the attenuation device, and the control means controls the magnetic field forming means of each attenuation device based on the detection value of the corresponding accelerometer. Features. According to the present invention, the control device can perform optimal control based on the detection value of the accelerometer corresponding to each attenuation device, and can effectively attenuate the vibration of the structure.

The invention of claim 15 is characterized in that the control means controls the attenuation device based on external earthquake information. According to the present invention, the damping device can be operated based on external earthquake information, and the structure can be in a state in which the vibration of the structure is attenuated before the arrival of the seismic wave. An effective attenuation effect can be obtained.
The invention according to claim 16 is characterized in that the control means periodically drives the magnetic field forming means of the attenuation device to form a magnetic field in the sealed region. According to the present invention, since the control means periodically drives the magnetic field forming means of the magnetorheological fluid, the magnetic particles of the magnetorheological fluid can be chained to prevent their precipitation.

According to the damping device according to the present invention, small and externally applied vibration can be attenuated with desired characteristics by the inertia moment of the flywheel and the adjustable resistance force by the magnetorheological fluid. The magnetic viscous fluid exhibits a predetermined function even without applying vibration for the purpose.
Further, according to the structure damping device of the present invention, the damping characteristics of the damping device arranged in the structure can be adjusted in real time according to the characteristics and the excitation characteristics of the structure, It is possible to effectively perform vibration suppression suitable for the excitation characteristics.

It is sectional drawing of the attenuation device which concerns on one Embodiment of this invention. It is the perspective view which notched and showed a part of damping device of FIG. It is sectional drawing which expands and shows the principal part of the damping device of FIG. It is sectional drawing of the attenuation device which concerns on 2nd Embodiment. It is sectional drawing of the attenuation device which concerns on 3rd Embodiment. It is sectional drawing of the attenuation device which concerns on 4th Embodiment. It is sectional drawing of the attenuation device which concerns on 5th Embodiment. It is a mimetic diagram showing a vibration damping device of a structure concerning an embodiment of the present invention. It is a schematic diagram which shows the example of attachment of the attenuation device in the damping device of the structure of this invention. It is a schematic diagram which shows the example of attachment of the attenuation device in the damping device of the structure of this invention. It is a schematic diagram which shows the example of attachment of the attenuation device in the damping device of the structure of this invention. It is sectional drawing which shows an example of the conventional damping device.

  Hereinafter, an attenuation device according to an embodiment will be described with reference to the drawings. Several examples will be described below, but the present invention is not limited to the embodiments, and various improvements, changes, modifications, and substitutions are possible within the scope of the claims and the gist thereof. is there.

FIG. 1 is a cross-sectional view of an attenuation device according to one embodiment of the present invention, and FIG. 2 is a perspective view of the same attenuation device.
The damping device 1 includes a casing 30 composed of a first cylinder 10 and a second cylinder 20, a sleeve 40 disposed in the first cylinder 10, and a flywheel disposed in the second cylinder 20. 50 and magnetic field forming means 60 disposed in the second cylinder 20.

The first cylinder 10 is a cylindrical member having an axial through hole 13 having a tip opening 11 at the tip (left side in FIG. 1) and a communication opening 12 at the other end (right side). . The second cylinder 20 is fixed to the other end of the first cylinder 10 in the same axial center with the opening 21 at one end communicating with the communication opening 12 of the first cylinder 10. It is a hollow member. A lid member 22 is provided at the other end of the second cylinder 20, and a universal joint 23 is attached to the lid member 22 for connection to a structure or the like on which the damping device 1 is installed. The casing 30 is integrally formed of, for example, a steel material.
In the axial through hole 13 of the first cylinder 10, a hollow sleeve 40 having a distal end protruding from the distal opening 11 side is disposed so as to be able to advance and retract in the axial direction. The sleeve 40 is supported in the axial through hole 13 of the first cylinder 10 so as not to rotate but to advance and retract in the axial direction. That is, the sleeve 40 is supported by the bush 14 disposed in the first cylinder 10 so that the sleeve 40 can move forward and backward in the axial direction in the first cylinder 10, and It is supported so that it cannot rotate.

An attachment member 41 connected to a structure or the like on which the present damping device 1 is installed is fixed to the tip (left side in the figure) of the sleeve 40. Further, a ball nut 42 is fixed inside the other end portion (on the right side) of the sleeve 40, and a ball screw 43 that is screwed into the female screw portion is inserted into the ball nut 42. The ball screw 43 and the ball nut 42 make this linear movement highly efficient when the first cylinder 10 and the sleeve 40 are moved relative to each other in the axial direction due to vibration and impact applied from the structure or the like on which the damping device 1 is installed. Thus, it has a function of converting into the rotational motion of the ball screw 43.
A rotating shaft member 44 is connected to the other end of the ball screw 43 coaxially with the ball screw 43. The rotary shaft member 44 is provided so as to extend inside the second cylinder 20 and is rotated by a bearing 24 disposed on the inner periphery of the end flange 26 (boundary portion with the first cylinder) of the second cylinder 20. It is pivotally supported.
The shaft portion of the flywheel 50 is fixed to the rotating shaft member 44. As a result, the flywheel 50 rotates integrally with the second cylinder 20 as the ball screw 43 rotates. The flywheel 50 is made of a ferromagnetic material such as steel, and is a cylindrical member having end small diameter portions 51 and 52 formed at both ends. In the damping device 1, the vibration applied between the universal joint 23 and the mounting member 41 is attenuated by the moment of inertia of the flywheel 50. In addition, the code | symbol 27 in FIG. 1 has shown the nut for a flywheel assembly | attachment.

  A sealed region 46 is formed in the gap between the inner wall of the second cylinder 20 and the outer periphery of the flywheel 50. The sealed region 46 is formed by disposing seal members 47 and 48 between the end small diameter portions 51 and 52 of the flywheel 50 and the second cylinder 20. That is, one seal member 47 is disposed between the inner periphery of the inner flange portion 28 provided in the second cylinder 20 and the end small diameter portion 51 of the flywheel 50, and the other seal member 48 is a lid member. 22 and the other end small diameter portion 52 of the flywheel 50. Further, the inner peripheral wall of the second cylinder 20 forming the sealed region 46 and the outer peripheral wall of the flywheel 50 are configured as close as possible. For this reason, the volume of the sealed region 46 is small. The second cylinder 20 is closed at the end portion (right side in the drawing) by the seal member 48 and the end small diameter portion 52.

The sealed region 46 is filled with a magnetorheological fluid 49. Magnetorheological fluid (MR fluid) is a mixture of magnetic particles in base oil. When subjected to a magnetic field, the magnetic particles are connected in a chain, and when they are subjected to shear deformation or flow, resistance is exerted. Is generated. The magnitude of this resistance varies depending on the magnitude of the magnetic field applied, and rises to a certain extent as a stronger magnetic field is applied. In the damping device 1, since the volume of the sealed region 46 is small, the amount of the magnetorheological fluid 49 to be sealed may be smaller than that of the conventional type in which the magnetorheological fluid is sealed in the cylinder.
A magnetic field forming means 60 is disposed on the inner wall of the second cylinder 20. The magnetic field forming means 60 is an electromagnet that forms a magnetic field M across the sealed region 46 using the second cylinder 20 and the flywheel 50 as part of the magnetic circuit. In the damping device 1, the magnetic viscous fluid 49 in the sealed region 46 imparts resistance to the flywheel 50 due to shearing of the magnetic viscous fluid 49 by the magnetic field M.

Next, the magnetic field forming means 60 will be described. FIG. 3 is an enlarged cross-sectional view illustrating a main part of the attenuation device according to the embodiment. The magnetic field forming means 60 includes a plurality of, for example, four coils 61 arranged on the inner circumference of the second cylinder 20, and yokes such as ferrite materials arranged at both ends of each coil 61 to induce magnetic lines of force. A magnetorheological fluid disposed between the member 62 and the inner diameter side of the coil 61 and between the yoke member 62 and between which the magnetic lines of force cannot pass, for example, a nonmagnetic member 63 made of stainless steel, and between the yoke member 62 and the nonmagnetic member 63 And a sealing member 64 for sealing.
In the magnetic field forming means 60, each coil 61 is configured so that the directions of adjacent magnetic fields M coincide with each other when each coil 61 is energized, and the second cylinder 20 and the magnetic field forming means 60 are part of the magnetic circuit. Magnetic field lines pass through. For this reason, the number of constituent members can be reduced when the magnetic field forming means 60 forms the magnetic field M across the sealed region 46. Further, since the magnetic lines of force are configured to pass through a member made of a ferromagnetic material except for the sealed region 46, the magnetic field M across the sealed region 46 can be formed with high efficiency, and a strong magnetic field can be obtained with a small amount of power consumption. Can be formed. Furthermore, in this example, since the inner peripheral surface of the second cylinder 20, that is, the magnetic field forming means 60 and the outer peripheral surface of the flywheel 50 are disposed close to each other, the magnetic field M is more efficiently transferred into the sealed region 46. Can be formed. Further, the resistance due to the magnetorheological fluid 49 increases as the thickness of the magnetorheological fluid layer decreases, so that a greater resistance can be applied to the flywheel 50.

In the damping device 1, when vibration is applied to the attachment members 41 and the universal joint 23 at both ends, the linear motion component of the vibration is efficiently converted into rotational motion by the ball nut 42 and the ball screw 43, thereby causing the flywheel 50 to move. Rotate. When a current is passed through the coil 61 of the magnetic field forming means 60, the magnetic field M crosses the magnetic viscous fluid 49 in the sealed region 46, and the magnetic particles of the magnetic viscous fluid 49 are between the magnetic field forming means 60 and the flywheel 50. The chain of ferrofluid particles is sheared by the rotation of the flywheel 50, and resistance is given to the flywheel 50.
Therefore, the vibration applied to the damping device 1 is effectively damped by the moment of inertia of the flywheel 50 and the resistance of the magnetorheological fluid to the rotation of the flywheel 50. At this time, since the resistance of the flywheel by the magnetorheological fluid can be adjusted by changing the current applied to the coil 61 of the magnetic field forming means 60, the damping characteristic of the damping device 1 can be set to a desired value.

  In the damping device 1, the dimension between the magnetic field forming means 60 disposed on the inner wall of the second cylinder 20 in the sealed region 46 and the outer peripheral surface of the flywheel 50 is caused by steady vibration when the damping device 1 is used. It is desirable that the dimensions be small enough to agitate the encapsulated magnetorheological fluid so that precipitation does not occur due to the rotation of the flywheel. For example, when the damping device 1 is used for a structure such as a building, the flywheel 50 of the damping device 1 is slightly rotated by the passing vibration of the vehicle constantly applied to the building. The magnetorheological fluid 49 in the sealed region 46 is agitated by the minute rotation of the flywheel 50, and the precipitated magnetic particles are mixed with the base oil, so that the performance of the magnetorheological fluid can be exhibited. The distance between the flywheel 50 and the magnetic field forming means 60 varies depending on conditions such as the building actually used, and is determined by experiments.

Next, another attenuation device according to the embodiment of the present invention will be described. FIG. 4 is a cross-sectional view of an attenuation device according to the second embodiment. The same parts as those in the first embodiment will be described with the same reference numerals.
The damping device 71 according to this embodiment is obtained by reversing the positions of the ball nut 42 and the ball screw 43 in the damping device 1 according to the first embodiment. And the structure of the attachment member accompanying the change of the position of the ball nut 42 and the ball screw 43 is the same as that of the first embodiment except that the shape of the mounting member is changed from that of the first embodiment.
That is, the damping device 71 includes a casing 30 composed of the first cylinder 10 and the second cylinder 20, and the sleeve 40 is disposed in the first cylinder 10 so as to be able to advance and retract in the axial direction. One end of a ball screw 43 is fixed coaxially with the sleeve 40 on the second cylinder 20 side of the sleeve 40, the male screw portion of the ball screw 43 is screwed into the female screw portion of the ball nut 42, and further the ball A nut 42 is coaxially fixed to the center of a flywheel 50 disposed in the second cylinder 20.

Bearings 72 and 73 and seal members 74 and 75 are disposed between the outer periphery of both ends of the flywheel 50 in the axial direction and the second cylinder 20, respectively, and the flywheel 50 is rotatably held by the second cylinder. A sealed region 46 is formed between the inner wall of the second cylinder 20 and the outer periphery of the flywheel 50. The other end portion of the second cylinder 20 is closed with a lid member 22.
A magnetic field forming means 60 is disposed on the inner periphery of the second cylinder 20, and a magnetorheological fluid 49 is sealed in the sealed region 46.
The damping device 71 according to the second embodiment has the same operations and effects as the damping device 1 according to the first embodiment because only the positions of the ball nut 42 and the ball screw 43 are exchanged.

Next, an attenuation device according to a third embodiment will be described. FIG. 5 is a cross-sectional view of an attenuation device according to the third embodiment. The attenuation device 81 is the first embodiment except that an uneven portion is formed on the outer peripheral surface of the flywheel 82 and the shape of the yoke member 84 of the magnetic field forming unit 83 is changed in accordance with the shape of the uneven portion of the attenuation device 81. It has the same configuration as that of the example.
That is, in the damping device 81, the flywheel 82 is formed with a plurality of annular groove portions 85 at a predetermined pitch along the axial direction on the peripheral surface of the flywheel 82, so that the hook-shaped convex portions 86 are interposed between the annular groove portions 85. Is forming. Further, in the magnetic field forming means 83, the yoke member 84 is protruded to the inner diameter side so as to enter the annular groove portion 85 without contact.
According to the damping device 81, since the surface area of the flywheel 82 in contact with the magnetorheological fluid 49 is increased, even when the magnetic field forming unit 83 forms a magnetic field with the same electric power, compared with a case where the uneven portion is not provided. Thus, the resistance force that the flywheel receives from the magnetorheological fluid can be increased. Further, when forming the concavo-convex portion on the flywheel 82, it is sufficient to cut the rotating flywheel base material with a lathe or the like, so that the processing at the time of manufacturing the flywheel becomes easy. In addition, the uneven part is not limited to the combination of the annular groove part and the ridge-like convex part, and various shapes that can increase the surface area can be selected in addition to providing the uneven part along the axial direction.

  Next, an attenuation device according to a fourth embodiment will be described. FIG. 6 is a cross-sectional view of an attenuation device according to the fourth embodiment. The attenuation device 91 has the same structure as that of the first embodiment described above except that a permanent magnet 93 is used as the magnetic field forming unit 92. The permanent magnet 93 has a ring shape and is disposed at the same portion of the magnetic field forming unit 92 in place of the coil of the first embodiment. According to the damping device 91 according to this embodiment, viscosity can be imparted to the magnetorheological fluid without requiring a power source or the like, and vibration suppression can be performed with a simple configuration.

  Next, an attenuation device according to a fifth embodiment will be described. FIG. 7 is a cross-sectional view of an attenuation device according to the fifth embodiment. In the attenuation device 101, the magnetic field forming means 102 includes a permanent magnet 103 and a coil 104, and the other structure is the same as that of the first embodiment described above. In the attenuation device 101, the permanent magnet 103 constituting the magnetic field forming unit 102 has a ring shape and is disposed inside the coil 104. The permanent magnet 103 always forms a magnetic field across the sealed region 46 at all times. For this reason, the magnetic particles of the magnetorheological fluid are chained, and precipitation can be prevented. Further, in the attenuation device 101, the strength of the magnetic field M in the entire magnetic field forming unit 102 can be adjusted by adjusting the current flowing through the coil 104, and the viscous resistance applied to the flywheel 50 can be adjusted. For this reason, it is possible to obtain a vibration suppression characteristic that is optimal for a vibration suppression target.

Next, an embodiment of a structure damping device for a structure using the damping device according to the present invention will be described. FIG. 8 is a schematic view showing a structure damping device according to an embodiment of the invention. In this example, the damping device according to the first, second, third, or fourth embodiment described above is installed in the building 140 and is controlled by the control means 121.
In the structure damping device according to this embodiment, one end of the damping device 111, 112, 113 is connected to the ground 141, the structural member 142, 143, and the other end of the damping device 111, 112, 113 is connected to the coupling member 145, 146, 147, 148, 149, 150. In addition, the accelerometers 131, 132, 133, and 134 are disposed on the ground 141 and the structural members 142, 143, and 144, and the control unit 121 uses the attenuation devices 111 and 112 based on the detection values of the accelerometers 131, 132, 133, and 134. , 113 is adjusted to control the attenuation state. Further, an uninterruptible power supply (UPS) 122 is arranged in the control means 121 so that power can be supplied to the control means 121 even when a commercial power supply is interrupted.

In this example, the damping force of the damping devices 111, 112, and 113 is changed based on the response state of the ground 141 and the structural members 142, 143, and 144 detected by the accelerometers 131, 132, 133, and 134, and the entire building is changed. Can be controlled.
Note that how the attenuation device and the accelerometer are arranged in the building can be changed as appropriate. FIG. 9 to FIG. 11 are schematic views showing an example of attachment of an attenuation device in a structure damping device. In each example, each attenuation value device is controlled by the control means based on the detection value of the accelerometer arranged in the building, as in the above example.

In the example shown in FIG. 9, the attenuation devices 161, 162, and 163 are arranged in a bracing manner with respect to the ground 171 and the structural members 172, 173, and 174 that constitute each floor of the building 170.
Further, in the example shown in FIG. 10, the structural members 185, 186, and 187 of each floor of the building 184 and the structural members 189, 190, and 191 of each floor of the building 188 are respectively attenuated by the damping devices 181, 182, and 183. It is connected.
Furthermore, the example shown in FIG. 11 uses the damping device 201 for the seismic isolation structure of the building 200. In this example, laminated rubber isolators 202 and 203 are disposed between a building 200 and the ground 204 as a structure damping device, and a damping device is provided between the ground 204 and the structural member 205 constituting the lowermost layer of the building 200. 201 is arranged.

In each of the above examples, the control unit 121 controls the attenuation device based on an accelerometer arranged in the building. However, the control unit 121 can control the attenuation device based on external earthquake information. . As a result, the operation of the damping device can be started based on external earthquake information obtained in advance, and the structure can be put into a state of damping the vibration before the arrival of the seismic wave, and an effective damping effect can be obtained for the initial vibration. Can do.
In the present invention, the control means of the embodiment can drive the magnetic field forming means periodically to form a magnetic field in the sealed region of the attenuation device. As a result, the magnetic field forming means can be driven and the magnetic particles of the magnetorheological fluid can be chained to prevent the precipitation, and the damping device can exhibit its damping performance against suddenly applied earthquake vibration. .

DESCRIPTION OF SYMBOLS 1 Damping device, 10 1st cylinder, 11 Tip opening part, 12 Communication opening part, 13 Axial through-hole, 20 2nd cylinder, 21 opening part, 30 Casing, 40 Sleeve, 42 Ball nut, 43 Ball screw, 44 Rotating shaft member, 46 Sealed region, 47, 48 Seal member, 49 Magnetorheological fluid, 50 Flywheel, 60 Magnetic field forming means, 61 Coil, 62 Yoke member, 63 Non-magnetic member

Claims (16)

A first cylinder having an axial through-hole having a tip opening at the tip and a communication opening at the other end, and the first cylinder in a state where the one opening is in communication with the communication opening. A casing having a hollow second cylinder fixed in the same axial center to the other end of the cylinder and closed at the other end;
A hollow sleeve that fits within the tip opening of the first cylinder and is supported in the axial through hole so as not to rotate and to advance and retract in the axial direction;
A ball nut fixed in the sleeve;
A ball screw threadably engaged with the female screw portion of the ball nut;
A flywheel formed of a ferromagnetic material, rotatably disposed inside the hollow of the second cylinder, and fixedly driven coaxially with the ball screw;
A seal member that forms a sealed region in a gap between the inner wall of the second cylinder and the outer periphery of the flywheel;
Magnetic field forming means disposed on the inner wall of the second cylinder and forming a magnetic field across the sealed region with the flywheel as part of a magnetic circuit;
A magnetorheological fluid enclosed in the sealed region;
An attenuation device comprising: A first cylinder having an axial through-hole having a tip opening at the tip and a communication opening at the other end, and the first cylinder in a state where the one opening is in communication with the communication opening. A casing having a hollow second cylinder fixed in the same axial center to the other end of the cylinder and closed at the other end;
A hollow sleeve that fits within the tip opening of the first cylinder and is supported in the axial through hole so as not to rotate and to advance and retract in the axial direction;
A ball screw fixed in the sleeve;
A ball nut threadably engaged with the male screw portion of the ball screw;
A flywheel formed of a ferromagnetic material, rotatably disposed inside the hollow of the second cylinder, and fixedly driven coaxially with the ball nut;
A seal member that forms a sealed region in a gap between the inner wall of the second cylinder and the outer periphery of the flywheel;
Magnetic field forming means for forming a magnetic field that is disposed on the inner wall of the second cylinder and that traverses the sealed region using the flywheel as part of a magnetic circuit;
A magnetorheological fluid enclosed in the sealed region;
An attenuation device comprising:   3. The damping device according to claim 1, wherein the other end portion of the second cylinder and the sleeve are each provided with a connecting portion connected to an external member.   The attenuation device according to claim 1, wherein the magnetic field forming unit includes an electromagnet.   The attenuation device according to claim 1, wherein the magnetic field forming unit includes a permanent magnet.   The attenuation device according to claim 1, wherein the magnetic field forming unit includes an electromagnet and a permanent magnet.   The attenuation device according to any one of claims 1 to 6, wherein the magnetic field forming unit forms a magnetic field across the sealed region with the second cylinder as a part of a magnetic circuit.   The damping device according to any one of claims 1 to 7, wherein the flywheel includes an uneven portion on an outer periphery thereof.   8. The damping device according to claim 7, wherein the uneven portion of the flywheel includes an annular groove portion and a hook-like convex portion that are sequentially arranged in the axial direction of the flywheel.   The dimension between the inner wall of the second cylinder in the sealed region and the outer peripheral surface of the flywheel is encapsulated in the magnetorheological fluid by the rotation of the flywheel caused by steady vibration when the damping device is used. The damping device according to any one of claims 1 to 9, wherein the damping device has a size suitable for stirring to such an extent that does not precipitate.   A damping device according to any one of claims 1 to 10, which is mounted between structural members of a structure, and a control means for adjusting the magnetic force of a magnetic field forming means of the damping device. A structure damping device.   The structure damping device according to claim 11, further comprising an uninterruptible power supply for supplying power to the attenuation device and the control means. Comprising an accelerometer for detecting the state of vibration of the structure;
13. The structure damping device according to claim 12, wherein the magnetic force control means controls the magnetic field forming means based on a detection value of the accelerometer. The accelerometer is arranged corresponding to the damping device;
14. The structure damping device according to claim 13, wherein the control unit controls the magnetic field forming unit of each attenuation device based on a detection value of a corresponding accelerometer.   The structure damping device according to claim 11 or 12, wherein the control unit controls the damping device based on external earthquake information.   The structure control device according to any one of claims 11 to 15, wherein the control unit periodically drives the magnetic field forming unit of the attenuation device to form a magnetic field in the sealed region. apparatus.

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