Vibration control device

Abstract

To provide a vibration control device capable of suppressing an increase in a manufacturing cost and producing an excellent vibration damping effect according to predominant frequency of a constituent member due to a change in natural frequency of the constituent member of a building to be a vibration control target and external disturbance.SOLUTION: A vibration control device 100 which damps vibration on a constituent member F of a building comprises a tuned mass damper 10 and a control unit 80. The tuned mass damper 10 has switching means 70 which adjusts spring constant of a spring unit 30. The control unit 80 controls the switching means 70 by identifying predominant frequency of vibration on the constituent member F based on measurement data acquired through a vibration sensor 60 and determining the spring constant of the spring unit 30 suitable for vibration control based on a mass of a mass block 50 and the predominant frequency.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a vibration damping device. [Background technology]

[0002] Vibrations (vertical and horizontal vibrations) occur in the structural components of a building (or structure), such as floors, due to disturbances such as environmental vibrations. More specifically, microtremors occur constantly due to so-called environmental vibrations, such as traffic vibrations from trains and other vehicles, vibrations during the operation of factory equipment, vibrations due to wind loads, and even vibrations caused by walking indoors. To reduce the constant microtremor level shaking (acceleration) of such floors, tuned mass dampers (TMDs), which constitute vibration control devices, are sometimes installed on floors and the beams that support the floors.

[0003] Tuned mass dampers generally have their natural frequency and damping set to match the mass and natural frequency of the building's structural members that they are intended to damp, and the mass of the structural members and the spring stiffness of the springs that support the mass are set to achieve the set natural frequency. After a tuned mass damper is installed on a building's structural members, the natural frequency of the tuned mass damper is usually maintained at its initial set value (a constant value).

[0004] However, the vibration damping effect of the tuned mass damper can be reduced by changes in the natural frequency of the component to be damped due to changes in the stiffness of the component over time or changes in the mass of the component due to factors such as the load. Therefore, it is preferable that the natural frequency of the tuned mass damper be variable in response to changes in the natural frequency of the component, rather than being maintained at a constant value as described above. Furthermore, since the vibration damping effect of the tuned mass damper can be reduced even when the natural frequency of the tuned mass damper is not close to the dominant frequency of the component due to the disturbance, it is preferable that the natural frequency of the tuned mass damper be variable in response to the dominant frequency of the component due to the disturbance.

[0005] For these reasons, a tuned mass damper with a variable natural frequency is desirable. Because the natural frequency of a tuned mass damper is determined by the mass of the mass and the stiffness of the spring, as mentioned above, the natural frequency can be changed by changing the mass of the mass or the stiffness of the spring.

[0006] Here, Patent Document 1 proposes an installation system for residential vibration control devices in which a divided mass dynamic damper, each with elastically supported divided masses, is installed as a secondary vibration system for a house, which is a primary vibration system. In this installation system, divided mass dynamic dampers with 2 to 8 divided masses and set so that the natural frequency increases or decreases in increments of 0.1 to 0.8 Hz are standardized for each of a plurality of house frequency ranges, which are preset within a range of 2 to 8 Hz for the house's natural frequency, and when installing the divided mass dynamic dampers in an individual house, a standardized divided mass dynamic damper within a house frequency range that includes the house's natural frequency is selected and installed in the house.

[0007] Also, Patent Document 2 proposes an active floor vibration control device. This active floor vibration control device is equipped with a sensor for detecting vibrations of the floor to be controlled, a controller for controlling the actuator by determining the actuator operation amount that can reduce vibration and structure-borne sound from the detection signal from the sensor and a dynamic characteristic model of the floor to be controlled, and an actuator that is driven and controlled by the controller to generate an excitation force. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-120069 [Patent Document 2] Japanese Patent Application Laid-Open No. 2005-276118 Summary of the Invention [Problem to be solved by the invention]

[0009] The installation system for residential vibration control devices described in Patent Document 1 requires multiple divided masses with different corresponding frequency ranges in order to accommodate a wide range of residential natural frequencies, which poses the problem that the number of masses inevitably has to increase in order to accommodate the various natural frequencies.

[0010] On the other hand, the active floor vibration control device described in Patent Document 2 is an active mass damper (AMD) that detects vibrations with a sensor and dynamically moves a mass with an actuator, which necessitates precise control of the actuator to cancel out the acting excitation force, resulting in problems such as rising manufacturing costs.

[0011] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a vibration control device that can suppress increases in manufacturing costs and can achieve excellent vibration reduction effects in accordance with changes in the natural frequency of the constituent members of the building to be vibration-controlled and the predominant frequency of the constituent members due to external disturbances. [Means for solving the problem]

[0012] In order to achieve the above object, one aspect of the vibration damping device according to the present invention is A vibration control device that attenuates vibrations of building components, a tuned mass damper and a control unit; The tuned mass damper comprises: a stand that is directly or indirectly installed on the component; a spring unit installed on the frame, the spring unit including one or more main springs and a plurality of sub-springs; a mass supported by the spring unit; a switching means for switching between fixing and releasing a lower portion of the sub-spring and the base, A vibration sensor is installed on the platform, The control unit The method is characterized in that the predominant frequency of vibration of the component is identified based on the measurement data obtained from the vibration sensor, a spring stiffness suitable for vibration control is identified based on the mass of the mass and the predominant frequency, an optimal spring unit having the spring stiffness and consisting of one or more main springs and some or all of the multiple sub-springs is identified, and the switching means is controlled to form the optimal spring unit.

[0013] According to this aspect, the spring unit is comprised of one or more main springs and multiple sub-springs installed on a base, and a switching means for switching between fixing and unlocking the lower part of the sub-spring to the base, and the control unit identifies the predominant frequency of vibration of the component due to an external disturbance based on measurement data obtained from the vibration sensor, identifies the spring stiffness suitable for vibration control based on the mass of the mass and the predominant frequency, and controls the switching means to adjust the number of sub-springs that make up the spring unit to form an optimal spring unit, thereby suppressing increases in manufacturing costs and achieving an excellent vibration reduction effect in accordance with changes in the natural frequency of the component parts of the building to be vibration-controlled and the predominant frequency of the component parts due to external disturbances.

[0014] To maximize the vibration-damping effect of the constituent members of a building that are the target of vibration control, it is necessary to match the natural frequency of the vibration control device to the natural frequency of the constituent members, which can change for various reasons, and to maximize the vibration-damping effect of the constituent members when disturbances are acting, it is necessary to match the natural frequency of the vibration control device to the dominant frequency of the vibration of the constituent members, and this involves adjusting either the mass or spring stiffness of the mass that makes up the vibration control device.In this embodiment, the mass of the mass is set (fixed) in advance, and control is performed to adjust (change) the spring stiffness of the spring unit, thereby enabling effective control of the natural frequency of the vibration control device.

[0015] Here, "switching between fixing and releasing the lower part of the sub-spring to the frame" means that, for example, by abutting the lower end of the sub-spring against an actuator or the like fixed to the frame, the upper and lower ends of the sub-spring are fixed to the frame and the connecting member, and the sub-spring becomes a spring that contributes to spring stiffness; on the other hand, by moving the lower end of the sub-spring away from an actuator or the like fixed to the frame, the lower end of the sub-spring is released from the frame, and the sub-spring becomes a spring that does not contribute to spring stiffness.

[0016] Of the main spring and sub-springs that make up the spring unit, the main spring cannot be switched by a switching means and always contributes to spring stiffness, and by configuring multiple sub-springs around the main spring to be individually fixed and unlocked, it becomes possible to set the basic natural frequency of the tuned mass damper by the spring stiffness of the main spring, while adjusting the number of sub-springs that contribute to the spring stiffness to change the natural frequency of the tuned mass damper from the basic natural frequency as needed.In addition, examples of "building components" include the floors and walls that make up the building (interior partition walls and exterior walls).

[0017] In another aspect of the vibration damping device according to the present invention, The switching means an elevation table mounted on the base, which is movable up and down and can freely come into contact with lower ends of some or all of the plurality of sub-springs; an actuator for raising and lowering the lifting platform; The control unit operates the actuator to raise and lower the lifting platform, and brings the lifting platform into contact with the lower ends of the sub-springs in the number that forms an optimum spring unit.

[0018] According to this aspect, the lifting platform, which is raised and lowered by the actuator, abuts against the lower end of the sub-spring, thereby forming a stable fixed posture for the lower end of the sub-spring.

[0019] In another aspect of the vibration damping device according to the present invention, the plurality of sub-springs are sub-springs whose lengths gradually increase downward, and are arranged in order so that their lengths gradually change to form the spring unit; The upper surface of the lifting platform is a horizontal, flat surface.

[0020] According to this aspect, multiple sub-springs whose lengths gradually increase downward are arranged in order so that their lengths gradually change, and the upper surface, which is the horizontal, flat surface of the lifting platform, abuts against the lower end of each sub-spring, thereby adjusting the amount of lifting of the lifting platform, thereby making it possible to fine-tune the number of sub-springs that contribute to the spring stiffness, and thereby enabling continuous and efficient adjustment of the spring stiffness.

[0021] In another aspect of the vibration damping device according to the present invention, The sub-springs forming the spring unit all have the same length, The upper surface of the lifting platform is characterized in that it is an inclined surface or a stepped surface.

[0022] According to this aspect, the upper surface of the lifting platform, which is an inclined or stepped surface, abuts against the lower ends of multiple sub-springs, all of which are the same length, thereby adjusting the amount of lifting of the lifting platform and fine-tuning the number of sub-springs that contribute to the spring stiffness, thereby enabling continuous and efficient adjustment of the spring stiffness.

[0023] Another aspect of the vibration damping device according to the present invention is A plurality of the sub-springs are arranged at intervals around one of the main springs to form one spring unit, and each sub-spring is provided with its own lifting platform, or one lifting platform is provided that is common to all of the sub-springs.

[0024] According to this aspect, a single spring unit is formed by arranging multiple sub-springs at intervals in the circumferential direction around a single main spring, which makes it easier to specify the overall stiffness of the single spring unit. Furthermore, between a configuration in which each sub-spring is provided with its own lifting platform and a configuration in which a single lifting platform is provided common to all the sub-springs, the latter configuration in particular can further simplify the configuration of the switching means. In the latter configuration, a single lifting platform may be raised and lowered by a single actuator, or may be raised and lowered by multiple actuators that are synchronously controlled.

[0025] A plurality of spring units formed by arranging a plurality of sub-springs at intervals in the circumferential direction around one main spring may be installed on the upper surface of the mount. For example, in a flat-type tuned mass damper in which a mass is supported by a plurality of spring units, one spring unit may be located at the center of the mass in a plan view, or multiple spring units may be located at positions where they evenly support their respective shares of the mass of the mass.

[0026] Another aspect of the vibration damping device according to the present invention is A plurality of the main springs are mounted on the base at intervals, A plurality of sub-springs are arranged between a plurality of main springs to form one spring unit, and each sub-spring is provided with its own lifting platform, or one lifting platform is provided that is common to all the sub-springs.

[0027] According to this aspect, a single spring unit is constructed by arranging multiple sub-springs between multiple main springs, thereby forming a spring unit with a stable and balanced spring arrangement.

[0028] In another aspect of the vibration damping device according to the present invention, The control unit identifies an optimal spring unit consisting of one or more of the main springs and some or all of the multiple sub-springs so that the dominant frequency matches the natural frequency of the tuned mass damper, and controls the switching means to form the optimal spring unit.

[0029] According to this aspect, when a component is vibrating due to an external disturbance, the spring stiffness is adjusted so that the dominant frequency of the vibration of the component matches the natural frequency of the tuned mass damper, thereby forming an optimal spring unit, thereby enabling the tuned mass damper to achieve the maximum vibration reduction effect on the component.

[0030] In another aspect of the vibration damping device according to the present invention, the mass is attached to a connecting member, and the connecting member is supported by the spring unit; One end of the connecting member is rotatably or non-rotatably attached to the stand or to an upright member standing upright on the stand, and the other end of the connecting member is supported by the spring unit, The mass is attached to the connecting member, and is of a cantilever type.

[0031] According to this aspect, a cantilever-type vibration control device can be formed that can achieve excellent vibration reduction effects in accordance with changes in the natural frequency of the constituent components of the building to be vibration-controlled and the dominant frequency of the constituent components due to external disturbances.

[0032] Another aspect of the vibration damping device according to the present invention is The present invention is characterized in that it has a flat configuration in which a plurality of the spring units are attached to the mount and the mass is supported by the plurality of the spring units.

[0033] According to this aspect, a flat vibration damping device can be formed that can achieve excellent vibration reduction effects in accordance with changes in the natural frequency of the constituent members of the building to be damped and the dominant frequency of the constituent members due to external disturbances.

[0034] Another aspect of the vibration damping device according to the present invention is the component to be damped is a floor, The present invention is characterized in that at least the tuned mass damper is installed directly or indirectly on the floor.

[0035] According to this aspect, floor vibrations caused by environmental vibrations can be effectively reduced. Here, "the tuned mass damper is installed directly or indirectly on the floor" includes both a configuration in which the tuned mass damper is installed on the floor of a building and a configuration in which the tuned mass damper is indirectly installed on the floor by being installed on a beam or the like supporting the floor.

[0036] The tuned mass damper may also be installed on the floor slab of a double floor. By installing the tuned mass damper on the floor slab of a double floor in this way, floor vibrations caused by environmental vibrations can be effectively reduced while effectively utilizing the under-floor space of the double floor, such as a free-access floor, as an installation space for the tuned mass damper. [Effects of the Invention]

[0037] As can be understood from the above explanation, the vibration control device of the present invention can suppress increases in manufacturing costs and can achieve excellent vibration reduction effects in accordance with changes in the natural frequency of the constituent components of the building to be vibration-controlled and the predominant frequency of the constituent components due to external disturbances. [Brief explanation of the drawings]

[0038] [Figure 1] FIG. 1 is an overall configuration diagram of an example of a vibration damping device according to an embodiment, showing a state in which a tuned mass damper constituting an example of the vibration damping device is installed on a beam supporting a floor. [Figure 2] 2 is a view taken along the line II-II in FIG. 1, and is a plan view of the spring unit viewed downward from a midpoint of the spring unit. [Figure 3] 6 is a graph illustrating the vibration reduction effect of one example of a vibration damping device according to an embodiment, together with the vibration reduction effect of another reference example. [Figure 4]4 is a graph illustrating the vibration damping effect (difference in damping due to natural frequency) of an example of a vibration damping device according to an embodiment. [Figure 5A] 2 is an enlarged view of a portion V in FIG. 1, illustrating an example of a switching means and an example of a plurality of sub-springs. FIG. [Figure 5B] FIG. 5B is a diagram corresponding to FIG. 5A and illustrating an example of a switching means and another example of a plurality of sub-springs. [Figure 5C] FIG. 5B is a diagram corresponding to FIG. 5A and illustrates an example of a switching means and yet another example of a plurality of sub-springs. [Figure 6] FIG. 10 is a diagram illustrating an example of a combination of a main spring and a sub-spring that constitutes an optimal spring unit in which the floor natural frequency and the TMD natural frequency match. [Figure 7] FIG. 2 is a diagram illustrating an example of the hardware configuration of a control unit that forms a vibration damping device according to an embodiment. [Figure 8] FIG. 2 is a diagram illustrating an example of the functional configuration of a control unit that forms a vibration damping device according to an embodiment. [Figure 9] FIG. 10 is a side view of another example of a tuned mass damper that constitutes a vibration damping device according to an embodiment. [Figure 10A] 10 is a view taken along the arrow XX in FIG. 9, and is a plan view looking downward from a midpoint of the spring unit. [Figure 10B] FIG. 10B is a plan view corresponding to FIG. 10A and showing another example of the spring unit. DETAILED DESCRIPTION OF THE INVENTION

[0039] Hereinafter, vibration damping devices according to embodiments will be described with reference to the accompanying drawings. In this specification and the drawings, substantially identical components will be designated by the same reference numerals, and redundant description may be omitted.

[0040] [Vibration damping device according to the embodiment] An example of a vibration damping device according to an embodiment will be described with reference to Figures 1 to 10. Here, Figure 1 is an overall configuration diagram of an example of a vibration damping device according to an embodiment, showing a state in which a tuned mass damper constituting an example of a vibration damping device is installed on a beam supporting a floor. Also, Figure 2 is a view taken along arrows II-II in Figure 1, and is a plan view looking downward from a midpoint of a spring unit.

[0041] The target of vibration damping by the tuned mass damper 10 constituting the vibration damping device 100 shown in Figure 1 is a floor F (an example of a structural component) that forms a building, and the floor F in the illustrated example is a long concrete floor slab with a span of about 15 m between a pair of girders G. Between the pair of girders G are multiple sub-girders B that also support the floor F. Here, the structural component of the building that is the target of vibration reduction may be an exterior wall, an interior wall such as a partition wall, or the like, in addition to the floor in the illustrated example.

[0042] The main girder G and the secondary beams B are both formed from H-shaped steel (including I-shaped steel) of different dimensions, and a frame 20 constituting the tuned mass damper 10 is installed across the lower flanges B1 of the two secondary beams B, which have a lower beam height than the main girder G. Therefore, the tuned mass damper 10 in the illustrated example is installed indirectly on the floor F via the secondary beams B.

[0043] The vibration damping device 100 includes a tuned mass damper 10 and a control unit 80. Although the damping mechanism is not shown in the illustrated example of the vibration damping device 100, the vibration damping device 100 may be in a form that does not include a damping mechanism as shown, or in a form that includes a damping mechanism.

[0044] The tuned mass damper 10 is installed below the floor F, between two small beams B that support the floor F. This installation configuration makes it possible to effectively utilize the space under the floor as installation space for the tuned mass damper 10. Although not shown in the figures, there are other configurations in which the space under a double floor, such as a free access floor, can be effectively utilized as installation space for the tuned mass damper.

[0045] The tuned mass damper 10 comprises a base 20 installed on a pair of small beams B supporting a floor F, a spring unit 30 installed on the upper surface 21 of the base 20, a connecting member 40 supported by the spring unit 30, a mass 50 placed on the connecting member 40, and a switching means 70 for adjusting the spring stiffness of the spring unit 30.

[0046] More specifically, a rotating part 22 provided at one end of the upper surface 21 of the frame 20 and a rotating part 43 provided at one end of the lower surface 42 of the connecting member 40 are rotatably connected to each other, and the other end of the upper surface 21 of the frame 20 and the other end of the lower surface 42 of the connecting member 40 are connected by a spring unit 30, thereby forming a cantilever-type tuned mass damper.

[0047] 2, the spring unit 30 is composed of a main spring 30A located in the center and multiple sub-springs 30B arranged at intervals in the circumferential direction around the main spring 30A. The spring stiffness of the main spring 30A is greater than the spring stiffness of the sub-springs 30B, and all of the sub-springs 30B have the same spring stiffness. Note that the multiple sub-springs 30B may have different spring stiffnesses.

[0048] The spring stiffness of the spring unit 30 in the tuned mass damper 10 is the total stiffness of one main spring 30A and some or all of the multiple sub-springs 30B arranged around it.

[0049] A vibration sensor 60 is installed on one end side of the upper surface 21 of the stand 20. The vibration sensor 60 measures vibrations in the X1 direction, which is the vertical direction of the floor F, which is the target of vibration control, and the small beams B that support the floor F. More specifically, the vibrations measured by the vibration sensor 60 are vibrations of the floor F caused by environmental vibrations.

[0050] Here, environmental vibrations include traffic vibrations caused by the running of vehicles including railways, vibrations during operation of factory facilities (facility vibrations), and walking vibrations caused by walking indoors.

[0051] Micro-tremors occur constantly in floor F due to environmental vibrations, and in order to reduce the vibrations in the X1 direction at the level of micro-tremors constantly occurring in floor F, tuned mass damper 10 is installed to vibrate mass 50 in the X2 direction, which is the vertical direction, and this vibration at the level of micro-tremors is constantly measured by vibration sensor 60. Here, an accelerometer, speedometer, displacement meter, etc. is used as vibration sensor 60, and the measurement data will be acceleration data, speed data, displacement data, etc. depending on the type of sensor.

[0052] The control unit 80 is formed by a computer and is installed in a location different from the floor F or the beams G and B, but may, for example, be mounted on an installation stand (not shown) attached to the beams G and B in the same manner as the tuned mass damper 10.

[0053] The measurement data measured by the vibration sensor 60 is transmitted to the control unit 80 via wireless communication in the R1 direction, and the control unit 80, having acquired the measurement data, transmits an operation signal to the switching means 70 in the R2 direction to operate the hydraulic cylinder (an example of an actuator) that constitutes the switching means 70, and adjusts the number of sub-springs 30B that contribute to the spring stiffness so that the spring unit 30 has a spring stiffness suitable for damping the vibrations of the vibrating floor F. Here, the measurement data may be transmitted to the control unit 80 via a wire, and the operation signal may also be transmitted to the switching means 70 via a wire.

[0054] The control unit 80 identifies the predominant frequency of vibration of the floor F by frequency analysis such as Fast Fourier Transform (FFT) based on the measurement data acquired from the vibration sensor 60, identifies a spring stiffness suitable for damping the vibrating floor F based on the mass of the mass 50 and the identified predominant frequency, and controls the hydraulic cylinder 70, which is the switching means 70, to set the spring stiffness of the spring unit 30 to the identified spring stiffness. Here, the actuator constituting the switching means 70 may be an air cylinder, a motor, or a rack and pinion mechanism unit that rises and falls by the rotation of the motor, in addition to the hydraulic cylinder shown in the figure.

[0055] With regard to vibration damping of the floor F, it is possible to effectively reduce the vibration of the floor F when the natural frequency of the tuned mass damper 10 matches the natural frequency of the floor F or the predominant frequency when the floor F vibrates due to environmental vibration (when vibrates due to an exciting force). To this end, the vibration damping device 100 measures the vibration of the floor F using the vibration sensor 60, identifies the primary natural frequency of the floor F or the predominant frequency of the vibration of the floor F vibrating due to environmental vibration, and adjusts the spring stiffness of the spring unit 30 so that the natural frequency of the tuned mass damper 10 matches or nearly matches these identified values. The specific configurations of the switching means 70 that adjusts the spring stiffness of the spring unit 30 and the multiple sub-springs 30B will be described in detail below.

[0056] Next, the vibration reduction effect of an example of a vibration damping device according to the embodiment will be described with reference to Figures 3 and 4. The vibration damping device for which the damping reduction effect will be described with reference to Figures 3 and 4 is intended for a configuration that includes, for example, a damping mechanism with a small amount of damping, and since the amount of damping is small, a mechanism that makes the natural frequency of the vibration damping device variable (in the illustrated example, a mechanism that makes the natural frequency variable by adjusting the spring stiffness) is required.

[0057] Here, Fig. 3 is a graph illustrating the vibration reduction effect of an example of the vibration damping device according to the embodiment together with the vibration reduction effect of other reference examples, and is a graph showing an example of the acceleration transmission characteristics of a floor. Also, Fig. 4 is a graph illustrating the vibration reduction effect (difference in attenuation due to natural frequency) of an example of the vibration damping device according to the embodiment.

[0058] In the graph shown in Figure 3, the horizontal axis indicates the ratio of the dominant frequency of the disturbance to the natural frequency of the floor, and the vertical axis indicates the ratio of the floor acceleration to the disturbance excitation force. As shown in Figure 3, when there is no vibration control device (curve <1> ) shows that the acceleration transmission characteristics of the floor are at their maximum when the horizontal axis is "1" (when the natural vibration frequency of the floor and the dominant frequency of the disturbance are equal (this frequency is called the resonance frequency)). <4> ) is a configuration in which the damping characteristic is adjusted to be a relatively flat characteristic against fluctuations in the dominant frequency of the disturbance by optimizing the damping amount of the damping mechanism, and the same vibration reduction effect is obtained at the position B1 of the resonance frequency and at the position B2 shifted from the resonance frequency. On the other hand, when the damping amount of the damping mechanism is larger than the optimal value (curve <5> ) cannot achieve sufficient vibration reduction effect, and the damping amount is smaller than the optimum value (curve <3> ) vibration becomes small at the resonance frequency, and two peaks appear at frequencies before and after the resonance frequency, destroying the flat characteristics.

[0059] On the other hand, when the damping amount of the damping mechanism is set to zero (curve <2> ) creates a valley at the resonance frequency, minimizing vibration, but the peaks that appear at frequencies around the resonance frequency become larger.

[0060] In this way, when the natural frequency of the tuned mass damper is constant and the dominant frequency of the disturbance matches the natural frequency of the floor, a significant vibration reduction effect can be achieved. However, if the dominant frequency of the disturbance and the natural frequency of the floor change and no longer match, there may be cases where a sufficient vibration reduction effect cannot be achieved.

[0061] To address these inherent problems in conventional vibration control devices, as shown in Figure 4, it is possible to constantly achieve maximum vibration reduction in response to disturbances by changing the natural frequency of the tuned mass damper by adjusting the spring stiffness of the spring unit of the tuned mass damper as needed. That is, Figure 4 shows the case where the natural frequency of the vibration control device and the natural frequency of the floor are in resonance (curve <30> ), when the natural frequency of the vibration control device is 5% lower than the floor natural frequency, the position of the valley where the vibration reduction effect is maximum shifts to the left (the side where the dominant frequency of the disturbance is lower), and when the natural frequency of the vibration control device is 5% higher than the floor natural frequency, the position of the valley where the vibration reduction effect is maximum shifts to the right (the side where the dominant frequency of the disturbance is higher). In the characteristics shown in the graph in Figure 3, by changing the natural frequency of the tuned mass damper, the curve <2> This allows the position of the valley to be changed, making it possible to achieve a significant vibration reduction effect.

[0062] The vibration control device 100 shown in the figure takes advantage of these characteristics and has the function of identifying the dominant frequency of vibration of the floor F, which is the target of vibration control, in a form that does not include a damping mechanism or in a form that includes a damping mechanism with a small amount of damping, and adjusting the spring stiffness of the spring unit 30 in order to change the natural frequency of the tuned mass damper 10 according to the identified dominant frequency.

[0063] 1, the natural frequency of the tuned mass damper 10 can be changed relatively easily by changing the spring stiffness of the spring unit 30. Since the spring stiffness of the spring unit 30 can be continuously changed as described in detail below, the natural frequency of the tuned mass damper 10 can also be continuously changed accordingly.

[0064] In the vibration damping device 100, when the natural frequency of the tuned mass damper 10 matches the dominant frequency of the disturbance acting on the floor F to be damped (when the spring stiffness of the spring unit 30 is adjusted so that the natural frequency matches), the maximum vibration reduction effect on the floor F is achieved (the curve <2> (See A1 of the above).

[0065] By utilizing a technique for matching the natural frequency of the tuned mass damper 10 with the dominant frequency of the disturbance, the mass of the mass can be made significantly smaller than that of conventional tuned mass dampers. That is, while the mass of the mass in conventional tuned mass dampers is generally 1 to 3% of the mass of the object to be damped, the mass of the mass 50 of the tuned mass damper 10 constituting the vibration damping device 100 of the illustrated example can be reduced to approximately 0.1 to 0.3% of the mass of the object to be damped.

[0066] Disturbances acting on the floor F, such as foot traffic and equipment, have different dominant frequencies. However, if the natural frequency of the tuned mass damper is fixed, the dominant frequency of the disturbance and the natural frequency of the tuned mass damper 10 may differ, and the vibration of the floor F may not be reduced (see the curve in Figure 3). <2> A2 state).

[0067] Therefore, the spring stiffness of the spring unit 30 is adjusted by the switching means 70 so that the natural frequency of the tuned mass damper 10 that constitutes the vibration control device 100 matches the predominant frequency of the disturbance, and the natural frequency is controlled to match the predominant frequency of the disturbance.

[0068] Furthermore, when no disturbance is acting, the vibration of the object to be damped tends to increase at its natural frequency (first natural frequency). Therefore, the natural frequency of the tuned mass damper 10 constituting the vibration damping device 100 is initially set to the first natural frequency of the object to be damped.

[0069] Furthermore, when the vibration of the floor F caused by the environmental vibration subsides, the switching means 70 is controlled so that the spring stiffness of the tuned mass damper 10 matches or nearly matches the natural frequency (first-order natural frequency) of the floor F.

[0070] The tuned mass damper 10 that constitutes the vibration control device 100 does not constantly vibrate the mass in accordance with the vibration of the object to be damped, as in the active control system, but changes the spring stiffness of the spring unit 30 that supports the mass 50 to change the characteristics of the vibration system. Therefore, there is no need for a large-scale, complex drive mechanism or the like to constantly vibrate the mass.

[0071] As a result, the tuned mass damper 10 constituting the vibration control device 100 can suppress increases in manufacturing costs. Furthermore, it can provide an excellent vibration reduction effect in accordance with the dominant frequency of the constituent members due to disturbances. Even if the natural frequency of the floor F of the building to be damped changes from its initial value, the natural frequency of the tuned mass damper 10 can be adjusted in accordance with the changed natural frequency of the floor F, thereby providing an excellent vibration reduction effect.

[0072] Next, an example of a switching means and an example of multiple sub-springs that constitute the tuned mass damper 10, as well as an example of a combination of a main spring and sub-springs that constitute an optimal spring unit, will be described with reference to Figures 5A to 5C and 6. Here, in Figures 5A to 5C, the main spring 30A located in the center of the multiple sub-springs 30B is not shown.

[0073] First, in the example shown in Fig. 5A, a plurality of hydraulic cylinders 70 (five are shown in Fig. 5A) corresponding to each sub-spring 30B are embedded inside the pedestal 20, and pistons 72 constituting the hydraulic cylinders 70 are configured to be able to freely move in and out above and below the upper surface 21 of the pedestal 20. The pistons 72 of each hydraulic cylinder 70 are mounted with an elevator platform 26 having a flat upper surface 26a, and the lower ends 30b of each sub-spring 30B are able to freely abut against the upper surface 26a.

[0074] The plurality of sub-springs 30B arranged at intervals in the circumferential direction are all set to have the same length t0.

[0075] 1, the upper end of the main spring 30A is fixed to the lower surface 42 of the connecting member 40, and the lower end is fixed in contact with the fixed base 24 that protrudes upward from the upper surface 21 of the frame 20, and the main spring 30A is a spring that contributes to the spring rigidity of the spring unit 30. In other words, the lower end of the main spring 30A is not released from the fixed base 24 by the hydraulic cylinder 70.

[0076] As shown in FIG. 5A, each hydraulic cylinder 70 is controlled by the control unit 80 so that only one of them is driven, or so that multiple (including all) of them are driven synchronously. As the piston 72 of one or more hydraulic cylinders 70 rises upward in the Y1 direction, the lower ends 30b of one or more sub-springs 30B come into contact with the upper surface 26a of the lifting platform 26. The upper ends 30a of the one or more sub-springs 30B are fixed to the lower surface 42 of the connecting member 40, and the lower ends 30b are fixed in contact with the upper surface 26a of the lifting platform 26, so that the one or more sub-springs 30B contribute to the spring rigidity of the spring unit 30.

[0077] That is, the spring stiffness of the spring unit 30 changes depending on the number of sub-springs 30B that contribute to the spring stiffness of the spring unit 30.

[0078] In this way, by changing the number of sub-springs 30B whose lower ends 30b abut and are fixed to the upper surface 26a of the lifting platform 26, the spring rigidity of the spring unit 30 consisting of the main spring 30A and one or more sub-springs 30B can be adjusted.

[0079] 5B, multiple hydraulic cylinders 70 (two in the illustrated example) are embedded inside the pedestal 20, and pistons 72 constituting the hydraulic cylinders 70 are configured to be able to freely move in and out above and below the upper surface 21 of the pedestal 20. An annular lifting platform 26A with a flat upper surface 26a is mounted on the pistons 72 of the two hydraulic cylinders 70, and the lower ends 30b of each sub-spring 30B are able to freely abut against the upper surface 26a. Here, the number of hydraulic cylinders 70 that raises and lowers the lifting platform 26A may be one, or three or more.

[0080] The multiple sub-springs 30B, which are arranged at intervals in the circumferential direction, are multiple sub-springs 30B1 to 30B5, etc., whose lengths gradually increase downward, and are arranged in order in the circumferential direction so that their lengths t1 to t5, etc., gradually change.

[0081] 5B, the two hydraulic cylinders 70 are controlled by the control unit 80 to be driven synchronously, and for example, in the process of the piston 72 rising upward in the Y1 direction, only the lower end 30b of the sub-spring 30B1 having the longest length t1 abuts against the upper surface 26a of the lifting platform 26A, and the upper end 30a of the sub-spring 30B1 is fixed to the lower surface 42 of the connecting member 40, and the lower end 30b abuts against and is fixed to the upper surface 26a of the lifting platform 26A, thereby contributing to the spring rigidity of the spring unit 30. On the other hand, the other sub-springs 30B2 to 30B5, etc., whose lower ends 30b do not abut against the upper surface 26a of the lifting platform 26A, do not contribute to the spring rigidity of the spring unit 30.

[0082] By gradually raising the piston 72 of the hydraulic cylinder 70, the lower end 30b of the sub-spring 30B2, which has the next longest length t2, comes into contact with the upper surface 26a of the lifting platform 26A, and the sub-spring 30B2 also contributes to the spring stiffness of the spring unit 30, making the spring stiffness of the spring unit 30 greater than when only the sub-spring 30B1 is in contact with the lifting platform 26A.

[0083] By further raising the piston 72 of the hydraulic cylinder 70, the lower ends 30b of the other sub-springs 30B3 etc. come into contact with the lift table 26A, and the spring rigidity of the spring unit 30 becomes even greater.

[0084] On the other hand, in the example shown in FIG. 5C, all of the sub-springs 30B have the same length t6, but the upper surface of the lift table 26B has an inclined surface 26b.

[0085] As the piston 72 moves upward in the Y1 direction, the lower ends 30b of the sub-springs 30B, whose lower ends 30b are located at the highest position on the inclined surface 26b, come into contact with the inclined surface 26b in order, thereby contributing to the spring rigidity of the spring unit 30. Here, instead of an inclined surface, the upper surface may be a stepped surface.

[0086] As described above, in order to match the natural frequency of the tuned mass damper 10 (TMD natural frequency) with the predominant frequency of the disturbance or the first-order natural frequency of the floor as closely as possible, a spring unit having a standard spring stiffness is formed by the main spring and half of the sub-spring, as shown in Figure 6, and the number of sub-springs in this standard spring unit is increased or decreased by one, thereby making it possible to match the TMD natural frequency as closely as possible with the predominant frequency of the disturbance or the first-order natural frequency of the floor, which can change from time to time.

[0087] Next, an example of the hardware configuration and functional configuration of the control unit 80 that forms the vibration damping device 100 will be described with reference to Fig. 7 and Fig. 8. Here, Fig. 7 is a diagram showing an example of the hardware configuration of the control unit that forms the vibration damping device according to the embodiment, and Fig. 8 is a diagram showing an example of the functional configuration of the control unit that forms the vibration damping device according to the embodiment.

[0088] The control unit 80 is configured by an information processing device (computer) such as a relatively small controller, and has a size that allows it to be placed on a stand spanning two small beams B, for example, as described above.

[0089] The controller constituting the control unit 80 includes a CPU (Central Processing Unit) 81, a main memory device 82, an auxiliary memory device 83, a communication IF (interface) 84, and an input / output IF 85, which are interconnected by a connection bus 86. The main memory device 82 and the auxiliary memory device 83 are computer-readable recording media.

[0090] The CPU 81 is a central processing unit that performs overall control of the control unit 80, which is made up of a computer.

[0091] The main storage device 82 stores computer programs executed by the CPU 81, data processed by the CPU 81, etc. The main storage device 82 includes, for example, a flash memory, a RAM (Random Access Memory), and a ROM (Read Only Memory).

[0092] The auxiliary storage device 83 is used, for example, as a storage area that assists the main storage device 82, and stores computer programs executed by the CPU 81, data processed by the CPU 81, and the like.

[0093] The input / output IF 85 is an interface for inputting and outputting data to and from devices connected to the control unit 80 .

[0094] The communication IF 84 is an interface with a network to which the control unit 80 is connected. The communication IF 84 receives measurement data from the vibration sensor 60 and transmits command signals to the actuator 70 via various networks including public networks such as the Internet.

[0095] As shown in FIG. 8, the control unit 80 provides various functions of at least an acquisition unit 102, a calculation unit 104, an operation unit 106, a display unit 108, and a storage unit 110 by the execution of a program by a CPU 81.

[0096] The acquisition unit 102 acquires measurement data transmitted from the vibration sensor 60, which measures micro-movements of the floor F caused by disturbances at any time, and stores the data in the storage unit 110 each time.

[0097] The storage unit 110 further stores the mass of the mass 50 that constitutes the tuned mass damper 10 and the natural frequency (first natural frequency) of the floor F that is the target of vibration damping, which is specified in advance.

[0098] The calculation unit 104 identifies the dominant frequency of vibration of the floor F when a disturbance acts, by frequency analysis, based on the measurement data transmitted as needed.

[0099] Furthermore, the calculation unit 104 identifies the spring stiffness of the spring unit 30 suitable for damping the vibration of the floor F based on the mass of the mass 50 stored in the memory unit 110 and the identified dominant frequency of the vibration of the floor F.

[0100] As a preliminary design step, spring unit 30 having a reference spring stiffness is set based on the mass of mass 50 and the natural frequency of floor F, and the number of sub-springs 30B is set according to the amount of change in the natural frequency of tuned mass damper 10, to manufacture vibration damping device 100. After that, a pre-operation experiment is conducted using the manufactured vibration damping device 100, and the relationship between the natural frequency of tuned mass damper 10 and the control amount is confirmed, after which the control amount for operation is set.

[0101] The relationship between the amount of lift of the piston 72 of the hydraulic cylinder 70 and the number of sub-springs 30B with which the lower end 30b abuts, as well as the spring stiffness of the spring unit 30 to be formed, is specified in advance, and the memory unit 110 stores this relationship data.

[0102] Based on the above-mentioned relationship data in the memory unit 110, the calculation unit 104 determines the amount of lift of the piston 72 of the hydraulic cylinder 70 that will achieve the spring stiffness of the spring unit 30 that will be the identified optimal spring unit, and the operation unit 106 sends a command signal regarding the determined amount of lift to the two hydraulic cylinders 70, thereby performing synchronized drive control of the two hydraulic cylinders 70.

[0103] By individually driving or synchronously driving each hydraulic cylinder 70, the spring stiffness of the spring unit 30 can be adjusted to a spring stiffness suitable for damping vibrations of the floor F.

[0104] When the vibration of floor F caused by environmental vibration subsides, a command signal is sent from the operating unit 106 to the hydraulic cylinder 70, and the hydraulic cylinder 70 is driven and controlled so that the spring stiffness is such that the natural frequency of the tuned mass damper 10 matches the first-order natural frequency of floor F.

[0105] The display unit 108 displays the measurement data from the vibration sensor 60, which changes due to environmental vibrations (external disturbances), and further displays the dominant frequency of the vibration of the floor F identified based on the measurement data, and displays the spring stiffness of the spring unit 30 suitable for damping the vibration of the floor F.

[0106] Next, another example of a tuned mass damper constituting a vibration damping device according to an embodiment will be described with reference to Fig. 9, Fig. 10A, and Fig. 10B. Fig. 9 is a side view of another example of a tuned mass damper constituting a vibration damping device according to an embodiment. Fig. 10A is a view taken along the arrow XX in Fig. 9, showing a plan view looking downward from a midpoint of the spring unit. Fig. 10B is a plan view corresponding to Fig. 10A, showing another example of a spring unit.

[0107] The tuned mass damper 10A shown in Figures 9 and 10A differs from the tuned mass damper 10 in that the connecting member 40 carrying the mass 50 is of a flat type, supported by multiple (four in the illustrated example) spring units 30.

[0108] In the example shown in FIG. 10A, four spring units 30 are arranged so as to be located at the four corners of a square, for example.

[0109] In addition, the example shown in Figure 10B, which is a modified example of Figure 10A, similarly has four main springs 30A arranged at the four corners of a square, and multiple sub-springs 30B arranged evenly on all four sides in the center of the four main springs 30A.

[0110] Because of its flat shape, the connecting member 40 and the mass 50 mounted thereon reduce the vibration of the floor F as they vibrate in the X3 direction, which is the up-and-down direction, while maintaining a parallel posture as a whole.

[0111] In the flat-type tuned mass damper 10A shown in the figure, the overall stiffness of the four spring units 30 is adjusted to a spring stiffness suitable for damping vibrations of the floor F.

[0112] It should be noted that the configurations of the above-described embodiments may be combined with other components, and the present invention is not limited to the configurations shown here. In this regard, the present invention may be modified within the scope of the gist of the present invention, and may be appropriately determined depending on the application form. [Explanation of symbols]

[0113] 10, 10A: Tuned mass damper 20: Stand 21:Top surface 22: Rotating part 24:Fixed stand 26, 26A, 26B: Lift platform 26a: Flat surface (top surface) 26b: Inclined surface (top surface) 30: Spring unit 30A: Main spring 30B: Sub spring 30B1~30B5: Sub-spring 30a: Upper end 30b: Bottom end 40: Connecting member 41:Top surface 42: Bottom surface 43: Rotating part 50: Square 60: Vibration sensor 70: Switching means (hydraulic cylinder) 72: Piston 80: Control unit 100: Vibration control device F: Floor (component) B: Beam (small beam) B1: Lower flange G: Liang (girder)

Claims

1. A vibration control device that attenuates vibrations of building components, a tuned mass damper and a control unit; The tuned mass damper comprises: a stand that is directly or indirectly installed on the component; a spring unit installed on the frame, the spring unit including one or more main springs and a plurality of sub-springs; a mass supported by the spring unit; a switching means for switching between fixing and releasing a lower portion of the sub-spring and the base, A vibration sensor is installed on the platform, The control unit A vibration damping device characterized in that the predominant frequency of vibration of the component is identified based on measurement data obtained from the vibration sensor, a spring stiffness suitable for vibration damping is identified based on the mass of the mass and the predominant frequency, an optimal spring unit having the spring stiffness and consisting of one or more of the main springs and some or all of the multiple sub-springs is identified, and the switching means is controlled to form the optimal spring unit.

2. The switching means an elevation table mounted on the base, which is movable up and down and can freely come into contact with lower ends of some or all of the plurality of sub-springs; an actuator for raising and lowering the lifting platform; 2. The vibration damping device according to claim 1, wherein the control unit operates the actuator to raise and lower the lifting platform, and causes the lifting platform to abut against the lower ends of the number of sub-springs that form an optimum spring unit.

3. the plurality of sub-springs are sub-springs whose lengths gradually increase downward, and are arranged in order so that their lengths gradually change to form the spring unit; 3. The vibration damping device according to claim 2, wherein the upper surface of the lifting platform is a horizontal, flat surface.

4. The sub-springs forming the spring unit all have the same length, 3. The vibration damping device according to claim 2, wherein the upper surface of the platform is an inclined surface or a stepped surface.

5. 5. A vibration damping device as described in claim 3 or 4, characterized in that a plurality of sub-springs are arranged around one main spring at intervals in the circumferential direction to form one spring unit, and each sub-spring is provided with its own lifting platform, or one lifting platform is provided that is common to all sub-springs.

6. A plurality of the main springs are mounted on the base at intervals, 5. A vibration damping device as described in claim 3 or 4, characterized in that a single spring unit is formed by arranging a plurality of the sub-springs between a plurality of the main springs, and each sub-spring is provided with its own lifting platform, or a single lifting platform is provided that is common to all the sub-springs.

7. 5. The vibration damping device according to claim 3, wherein the control unit identifies an optimal spring unit consisting of one or more of the main springs and some or all of the plurality of sub-springs so that the dominant frequency matches the natural frequency of the tuned mass damper, and controls the switching means to form the optimal spring unit.

8. the mass is attached to a connecting member, and the connecting member is supported by the spring unit; One end of the connecting member is rotatably or non-rotatably attached to the stand or to an upright member standing upright on the stand, and the other end of the connecting member is supported by the spring unit, 5. The vibration damping device according to claim 3, wherein the mass is attached to the connecting member, and the vibration damping device is of a cantilever type.

9. 5. The vibration damping device according to claim 3, wherein the vibration damping device is of a flat type, in which a plurality of the spring units are attached to the mount, and the mass is supported by the plurality of the spring units.

10. the component to be damped is a floor, 5. The vibration damping device according to claim 3, wherein at least the tuned mass damper is installed directly or indirectly on the floor.

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