JP5323391B2 - Vibration suppression device - Google Patents

Description

  The present invention relates to a vibration suppressing device that suppresses horizontal vibration of a suspended object caused by an earthquake or wind.

As a conventional technology in such a field, there is JP-A-2001-12541. The vibration suppression device described in this publication is configured by providing a box on the upper end side of a suspended object suspended from a hanging tool (suspending material) and placing a reciprocating weight in the internal space of the box. Has been. In such a vibration suppressing device, the vibration of the suspended object is attenuated by the weight in the box reciprocatingly colliding with the wall surface in accordance with the horizontal vibration of the suspended object.
JP 2001-12541 A

  Here, in the above-described vibration suppression device, a separate device must be provided for the hanging object, so that it may not be applicable to some hanging objects due to appearance problems and cost problems. In addition, since the influence of the vibration of the structure itself increases with the increase in size and height of the structure in recent years, resonance occurs between the vibration system composed of the suspended object and the suspended material and the structure. However, even if the vibration device attenuates the vibration, there is a problem that the suspended object vibrates greatly until the vibration is attenuated. In particular, when a large suspended object is hung from a high position in a large facility, a large vibration may give a psychological fear to the person below.

  An object of this invention is to provide the vibration suppression apparatus which can suppress the increase in the vibration of the horizontal direction of a suspended object with simple structure.

  The vibration suppression device according to the present invention is a suspension vibration suppression device for suppressing an increase in horizontal vibration of a suspension suspended by a long suspension member in a structure. It is characterized by comprising a natural period changing means for changing the natural period of the vibration system composed of the suspension material and the suspended object by changing the above.

  In this vibration suppression device, the natural period changing means can change the hanging length of the suspended object and can change the natural period of the vibration system composed of the suspended material and the suspended object. Therefore, even if the natural period of the vibration system exists in the vicinity of the natural period such as a structure or the ground, and vibration increases due to resonance, resonance can be avoided only by changing the suspension length with the natural period changing means. be able to. Accordingly, it is possible to suppress an increase in the horizontal vibration of the suspended object with a simple configuration without separately providing a special vibration damping device.

  Moreover, it is preferable that a vibration suppression apparatus is further provided with the vibration prediction means which estimates the vibration of a suspended object and controls a natural period change means based on a prediction result. By predicting the vibration of a suspended object due to the shaking of the structure due to an earthquake, strong wind, etc., avoid the resonance by changing the suspension length with the natural period changing means before the suspended object vibrates greatly due to resonance. Can do. Furthermore, if it is predicted whether or not the vibration due to the earthquake or strong wind and the vibration system of the suspension will resonate, the natural period changing means can be controlled only when the vibration of the suspension becomes large. It is possible to prevent control.

  Moreover, in the vibration suppressing device, it is preferable that the vibration predicting means predicts the vibration of the suspended object based on the earthquake early warning. By predicting the vibration based on the earthquake early warning, it is possible to predict the vibration before the vibration is transmitted to the suspended object and change the natural period in advance when an earthquake occurs far from the structure. it can.

  Moreover, in the vibration suppressing device, it is preferable that the vibration predicting means predicts the vibration of the suspended object based on the initial tremor of the earthquake. By predicting the vibration based on the initial tremor, if the earthquake occurs in an area close to the structure, such as a direct earthquake, the vibration of the suspended object is predicted before the main motion is transmitted, and the natural period is Can be changed.

  In the vibration suppression device, the prediction is preferably performed based on the seismic wave characteristics of the earthquake. Compare the seismic wave characteristics of the earthquake obtained from the contents of the earthquake early warning and the analysis result of the initial tremor and the natural period of the vibration system of the suspended object. The period can be changed.

  In the vibration suppressing device, the prediction is preferably performed based on the vibration characteristics of the ground. When considering the vibration characteristics of the ground between the hypocenter and the structure, comparing the vibration characteristics of the ground near the structure with the natural period of the vibration system of the suspension, and predicting the possibility of resonance The natural period of the vibration system can be changed.

  In the vibration suppression device, the prediction is preferably performed based on the vibration characteristics of the structure. When the vibration characteristics of the structure and the natural period of the suspension vibration system are compared, and the possibility of resonance is predicted, the natural period of the vibration system can be changed.

  Moreover, it is preferable that a vibration suppression apparatus is further provided with the vibration detection means which detects the vibration of a suspended object and controls a natural period change means based on a detection result. By detecting that the suspended object actually vibrates due to the shaking of the structure due to an earthquake or a strong wind, the natural period changing means can be accurately controlled in accordance with the actual suspended object vibration.

  In the vibration suppressing device, it is preferable that the vibration detecting unit includes a vibration determining unit that determines whether or not the detected vibration increases and controls the natural period changing unit based on the determination result. By analyzing the detected vibration and determining whether the vibration of the hanging object will increase, the natural period changing means can be controlled only when the vibration of the hanging object increases, and control is performed when it is not necessary. Can be prevented.

  Moreover, in the vibration suppressing device, it is preferable that the natural period changing unit includes a midway position fixing unit that changes a suspension length by fixing a midway position of the suspension member. By fixing the midway position of the suspension material with the midway position fixing means, the end position of the suspension length can be changed from the fixed position between the suspension material and the suspended object to the position of the midway position fixing means. Thereby, the natural length of the vibration system can be changed by changing the suspension length.

  In the vibration suppressing device, it is preferable that the natural period changing unit includes a vibration regulating unit that regulates horizontal vibration of the hanging material at a midway position of the hanging material. By restricting the vibration at the midway position of the suspension material by the vibration restricting means, the suspension material bends at the position of the vibration restricting means, so that the suspended object substantially vibrates with the position of the vibration restricting means as a fulcrum. As a result, the starting end position of the suspension length can be substantially changed from the fixed portion on the ceiling side of the suspension material to the position of the vibration restricting means, so the suspension cycle is changed to change the natural period of the vibration system. be able to.

  Further, in the vibration suppressing device, it is preferable that the vibration restricting means descend from the ceiling side of the structure when changing the natural period of the vibration system. Only when the natural period of the vibration system needs to be changed by the vibration regulating means descending from the ceiling side when changing the natural period of the vibration system, the amplitude at the midway position of the suspension material can be restricted. it can.

  Further, in the vibration suppression device, the natural period changing means is connected to a fixing member fixed at a midway position of the suspension member, a plurality of auxiliary suspension members whose one end side is connected to the fixing member, and the other end side of the auxiliary suspension member. And pulling the other end side of the auxiliary suspension member to tension the auxiliary suspension member when changing the natural period of the vibration system, and having a pulling means for restricting the horizontal movement of the fixing member. Is preferred. If the auxiliary suspension member is loosened at the normal time, the fixing member can be moved in the horizontal direction, and the fixing member and the auxiliary suspension member can vibrate together with the suspended object with the fixed portion on the ceiling side of the suspension member as a fulcrum. On the other hand, when the natural period is changed, the suspended object can be vibrated using the fixed member as a fulcrum by tensioning the auxiliary suspension member with the traction means to restrict horizontal vibration of the fixed member. Thereby, since the starting end position of the suspension length can be changed from the fixed portion on the ceiling side of the suspension member to the position of the fixation member, the suspension cycle can be changed to change the natural period of the vibration system.

  Moreover, in the vibration suppressing device, it is preferable that the natural period changing means has an elastic member connected to the suspension member. By connecting the elastic member to the suspension member, the elastic member expands and contracts with the change of the centrifugal force acting on the suspended object, and the suspension length can be changed. That is, when the vibration is large, a large centrifugal force acts on the suspended object, so that the length of the suspended member can be increased by increasing the elongation of the elastic member, thereby changing the natural period of the vibration system. it can.

  According to the present invention, it is possible to suppress an increase in horizontal vibration of a suspended object with a simple configuration.

  Hereinafter, a vibration suppressing device according to the present invention will be described in detail with reference to the drawings.

[First Embodiment]
The vibration suppression device according to the present embodiment, for example, in a structure such as a high-rise building or a large facility, when hanging a lighting device such as a chandelier, equipment, or a suspended object such as a suspended ceiling from the ceiling, When the suspended object vibrates due to the shaking of the structure due to the influence of an earthquake or wind, or when there is a possibility that the suspended object will vibrate, the increase in the horizontal vibration of the suspended object is suppressed. As shown in FIG. 1, the vibration suppressing device 1 includes a vibration system 4 configured by suspending a suspended object 2 from a ceiling F of a structure with a suspended material 3 such as a wire, and a winding for winding the suspended material 3. A device (natural period changing means) 5, a mechanical starting unit 6 that starts the winding device 5 with a mechanical trigger, and a control unit that controls the winding device 5 by predicting and detecting vibration of the suspension 2. 7, an earthquake early warning receiving unit 8 electrically connected to the control unit 7, a seismometer 9, and a vibration detection sensor (vibration detection means) 10.

  The winding device 5 is installed behind the ceiling F, and winds and rewinds the upper end portion of the suspension member 3 by rotating the pulley with a motor. The winding device 5 can change the suspension length of the suspended object 2 by winding and unwinding the suspension member 3, thereby changing the natural period of the vibration system 4. The winding device 5 is activated by a control signal from the control unit 7 or an operation of the mechanical activation unit 6, and the suspension length is shortened so that the vibration system 4 can avoid resonance with the structure S or the ground. Or it can be long.

  The mechanical starting unit 6 is configured by incorporating a mechanical switch or the like into the winding device 5 and has a function of starting the winding device 5 when the horizontal vibration of the hanger 2 exceeds a predetermined level. ing. Examples of the mechanical activation unit 6 include a mechanism that unlocks and activates the winding device 5 when vibration of a predetermined level or higher is applied.

  The emergency earthquake bulletin receiving unit 8 has a function of receiving an emergency earthquake bulletin transmitted from the Japan Meteorological Agency based on the measurement results of seismometers arranged in various parts of the country and outputting it to the control unit 7. By receiving this earthquake early warning, it is possible to acquire earthquake information such as the magnitude, epicenter and time of occurrence of the earthquake.

  The seismometer 9 is installed in the structure S as an on-site warning sensor for forecasting an earthquake. The seismometer 9 detects the vibration of the earthquake reaching the structure S and outputs the vibration information to the control unit 7. It has a function to do. The seismometer 9 can also detect an initial microtremor (P wave) which is a small shake of 2 to 3 seconds from the initial motion of the earthquake.

  The vibration detection sensor 10 is attached to the ceiling F of the structure or the suspended object 2, and has a function of detecting actual vibration acting on the vibration system 4 and outputting a detection result to the control unit 7. In addition, as the vibration detection sensor 10, both those installed on the ceiling F and those installed on the suspended object 2 may be used, or one of them may be used.

  The control unit 7 is electrically connected to the winding device 5 to perform control. For example, the control unit 7 is configured mainly by a CPU and includes a ROM, a RAM, an input signal circuit, an output signal circuit, a power supply circuit, and the like. . This control part 7 is based on the vibration prediction part 11 which predicts the vibration of the hanger 2, the vibration determination part 12 which determines whether the vibration of the hanger 2 directly detected increases, and a prediction result and a determination result. And an electric starter 13 for starting the winding device 5, and functions as vibration prediction means, vibration detection means, and vibration determination means.

  The vibration predicting unit 11 has a function of predicting the vibration of the suspended object 2 based on the earthquake information output from the emergency earthquake early warning receiving unit 8 or the vibration information output from the seismometer 9. The vibration prediction unit 11 outputs the prediction result to the electrical activation unit 13.

  Specifically, the vibration predicting unit 11 evaluates the seismic wave characteristics based on the magnitude of the magnitude, the position of the epicenter, and the like by comparing the earthquake information from the earthquake early warning receiving unit 8 with data stored in advance. Then, the vibration characteristics of the ground from the epicenter to the structure S and the vibration characteristics of the ground near the structure S are evaluated, and further, the vibration characteristics of the structure S itself are evaluated. The vibration prediction unit 11 compares these evaluation results with the natural period of the vibration system 4 of the suspended object 2 and determines whether there is resonance from the relationship between the natural period of the vibration system 4 and the natural period of the structure S, the ground, or the like. By taking into consideration, the magnitude of the vibration of the hanger 2 can be predicted. Such prediction based on the emergency vibration bulletin can be processed in a stage before the earthquake arrives, and thus is particularly effective when an earthquake occurs far away from the structure S.

  In addition, the vibration prediction unit 11 evaluates the seismic wave characteristics of the earthquake reaching the structure S by comparing the vibration information from the seismometer 9 with the data stored in advance, and the vibration prediction unit 11 The vibration characteristics and the vibration characteristics of the structure S are evaluated. The vibration prediction unit 11 compares these evaluation results with the natural period of the vibration system 4 of the suspended object 2 and determines whether there is resonance from the relationship between the natural period of the vibration system 4 and the natural period of the structure S, the ground, or the like. By taking into consideration, the magnitude of the vibration of the hanger 2 can be predicted. Thus, the prediction based on the vibration information detected by the seismometer 9 can be processed even at the initial tremor stage. Therefore, it is particularly effective when an earthquake occurs in an area close to the structure S, such as a direct earthquake, and the processing by the emergency earthquake warning is not in time.

  The vibration determination unit 12 has a function of determining whether or not the vibration increases by comparing the detection result from the vibration detection sensor 10 with the vibration data stored in advance. The vibration determination unit 12 outputs the determination result to the electrical activation unit 13. Thus, by determining based on the actual vibration of the suspended object 2 by the vibration detection sensor 10, it is possible to deal with vibrations caused by causes other than earthquakes such as wind. In addition, it is possible to cope with a case where an earthquake is not predicted in time.

  The electrical activation unit 13 has a function of activating the winding device 5 based on the prediction result output from the vibration prediction unit 11 or the determination result output from the vibration determination unit 12. Specifically, when the natural period of the vibration system 4 exists in the vicinity of the natural period of the structure S, the ground, etc., and it is predicted and determined that the suspended object 2 vibrates greatly due to resonance, the electrical activation unit 13 The suspension length that can avoid the resonance is calculated, and a control signal is output to the winding device 5 so that the calculated suspension length is obtained. In addition, since the earthquake which occurred far away from the structure S has a relatively large long-period component, resonance is often avoided by shortening the suspension length and shortening the natural period. In addition, since earthquakes that occur in the vicinity of the structure S have a relatively large number of short period components, resonance is often avoided by increasing the suspension length and the natural period.

  Next, with reference to FIG.2 and FIG.3, operation | movement of the vibration suppression apparatus 1 which concerns on 1st Embodiment is demonstrated.

  The process shown in FIG. 2 is a process for controlling the winding device 5 by predicting the vibration of the hanger 2 based on the vibration information such as the earthquake information based on the earthquake early warning and the initial tremor by the seismometer 9. This process is repeatedly executed at a predetermined timing in the control unit 7 while the vibration suppressing device 1 is activated.

  First, when an earthquake early warning is received by the earthquake early warning receiving unit 8 or when an initial microtremor is detected by the seismometer 9 (S100), the vibration predicting unit 11 performs an analysis of magnitude, location of the epicenter, vibration analysis, and the like. Based on the evaluation of the seismic wave characteristics (S102), the vibration characteristics of the ground from the epicenter to the structure S and the ground in the vicinity of the structure S are evaluated (S104). Is evaluated (S106). And the vibration prediction part 11 predicts the magnitude | size of the vibration of the hanging object 2 by comparing an evaluation result and the natural period of the vibration system 4 of the hanging object 2 (S108), and in order to avoid resonance, It is determined whether or not the natural period of the vibration system 4 needs to be changed (S110). If it is determined that the natural period does not need to be changed, the process of FIG. 2 ends, and a state of waiting for detection by the earthquake early warning receiving unit 8 and the seismometer 9 is entered.

  On the other hand, when it is determined in S110 that the natural period of the vibration system 4 exists near the natural period of the structure S, the ground, etc., and the natural period of the vibration system 4 needs to be changed, the electrical activation unit 13 The suspension length that can avoid resonance is calculated (S112), and a control signal is output to the winding device 5 (S114), and the processing of FIG.

  Next, the process of FIG. 3 will be described. This process is a process for controlling the winding device 5 when the vibration of the hanger 2 is directly detected by the vibration detection sensor 10. This process is repeatedly executed at a predetermined timing in the control unit 7 while the vibration suppressing device 1 is activated.

  First, when the vibration of the suspended object 2 is detected by the vibration detection sensor 10 (S200), the vibration determination unit 12 determines whether or not the magnitude of the vibration is equal to or lower than a predetermined level (S202). .

  When it is determined that the magnitude of the vibration of the hanging object 2 is equal to or lower than the predetermined level, the vibration determining unit 12 compares the detected characteristic of vibration with the data stored in advance, thereby The characteristics of the vibration are evaluated (S204), and based on the evaluation result, it is determined whether there is a possibility that the vibration of the hanger 2 is increased (S206). If it is determined that there is a possibility that the vibration of the suspended object 2 may increase due to resonance or the like, the electrical activation unit 13 calculates a suspension length that can avoid the resonance (S208), and controls the winding device 5 A signal is output (S210), and the process of FIG. 3 ends, and a state of waiting for detection by the vibration detection sensor 10 is entered. Even when it is determined in S206 that there is no possibility that the vibration of the suspended object 2 will increase, the process of FIG.

  On the other hand, when it is determined in S202 that the magnitude of the vibration of the suspended object 2 is greater than the predetermined level, a suspension length that can avoid resonance is calculated in order to quickly reduce the vibration (S208). A control signal is output to the capturing device 5 (S210).

  As described above, according to the vibration suppression device 1 according to the first embodiment, the winding device 5 changes the suspension length of the suspended object 2, and the vibration is configured by the suspended material 3 and the suspended object 2. The natural period of the system 4 can be changed. Therefore, even when the natural period of the vibration system 4 exists in the vicinity of the natural period of the structure, the ground, etc., and the vibration may increase due to the resonance, only the suspension length is changed by the winding device 5. Therefore, resonance can be avoided. Accordingly, it is possible to suppress an increase in the horizontal vibration of the suspended object with a simple configuration without separately providing a special vibration damping device.

  Further, by predicting the vibration of the suspended object 2 accompanying the shaking of the structure S due to an earthquake or the like, resonance can be avoided before the suspended object 2 vibrates greatly. Furthermore, if it is predicted whether or not it will resonate due to vibration caused by an earthquake, the winding device 5 can be controlled only when the vibration of the hanger 2 becomes large, and control can be prevented when it is unnecessary.

  In addition, by predicting vibration based on the earthquake early warning, when an earthquake occurs far from the structure S, the vibration is predicted before the vibration is transmitted to the suspended object 2, and the natural period is changed in advance. I can keep it.

  Also, by predicting the vibration based on the initial tremor, if the earthquake occurs in an area close to the structure S, such as a direct earthquake, the vibration of the suspended object 2 is predicted before the main motion is transmitted. The natural period can be changed in advance.

  Further, by detecting that the suspension 2 has actually vibrated with the shaking of the structure S, the control can be accurately performed corresponding to the actual vibration of the suspension 2. Further, by analyzing the detected vibration and determining whether or not the vibration of the suspended object 2 is increased, the winding device 5 can be controlled only when the vibration of the suspended object 2 is increased. It is possible to prevent control.

  In the present embodiment, the vibration can be predicted based on both the earthquake early warning and the vibration information of the seismometer 9, so that the vibration can be reliably predicted even when the epicenter is near or far. Furthermore, since the suspension length can be changed by the operation of the mechanical starting portion while being controlled based on the actual vibration of the suspended object 2, resonance can be accurately avoided regardless of the situation.

[Second Embodiment]
Next, a vibration suppressing device according to the second embodiment will be described. The vibration suppression device according to the second embodiment is the vibration suppression device 1 according to the first embodiment in that the natural cycle changing mechanism 20 shown in FIG. 4 is applied as the natural cycle changing means instead of the winding device 5. The main difference.

  As shown in FIG. 4, the natural period changing mechanism 20 is provided with a fixing plate 23 for fixing the lower end of the hanging material 22 inside a cylindrical hanging object 21, and a midway position fixing unit on the upper end side inside the hanging object 21. (Intermediate position fixing means) 24 is provided. The midway position fixing unit 24 has a function of changing the suspension length by fixing the midway position of the suspension member 22. Specifically, as shown in FIG. The suspension member 22 can be fixed by winding the one end side of the wire 26 wound around the wire 26 with the winding device 27. Alternatively, as shown in FIG. 5B, the suspension member 22 can be fixed by being sandwiched between the pressing plates 28. Such a winding device 27 may use a cord winding mechanism of a vacuum cleaner, and the pressing plate 28 may use a mechanism used for a knock mechanism of a ballpoint pen, or an external power source such as an electric motor. You may drive using.

  According to the natural period changing mechanism 20, before the suspension length is changed, the suspended object 21 vibrates at the suspension length L with the position of the fixed plate 23 as the end position of the suspension length, as shown in FIG. . On the other hand, after the suspension length is changed, as shown in FIG. 4B, the middle position of the suspension member 22 is fixed by the midway position fixing portion 24, and the fixed position is set as the end position. It can be '. Thereby, the natural length of the vibration system can be changed by changing the suspension length.

[Third Embodiment]
Next, a vibration suppressing device according to the third embodiment will be described. The vibration suppressing apparatus according to the third embodiment is the vibration suppressing apparatus 1 according to the first embodiment in that the natural period changing mechanism 40 shown in FIG. 6 is applied as the natural period changing means instead of the winding device 5. The main difference.

  As shown in FIG. 6, the natural period changing mechanism 40 is accommodated inside the large cylinder 43 so as to surround the hanging material 42 and the large cylinder 43 arranged so as to surround the hanging material 42 behind the ceiling F. And a small cylinder (vibration regulating means) 44. When the natural period of the vibration system is changed, the small cylinder 44 has a function of regulating the vibration of the suspension member 42 in the midway position by being lowered from the large cylinder 43 through the hole in the ceiling F. Yes. The small cylinder 44 may be moved using an electric motor, or a mechanical expansion / contraction mechanism may be used.

  According to such a natural period changing mechanism 40, the suspended object 41 vibrates at the suspended length L as shown in FIG. On the other hand, after the suspension length is changed, as shown in FIG. 6 (b), the suspended body 41 is substantially made up of the small cylinder body by regulating and bending the vibration at the midway position of the suspension material 42 with the small cylinder body 44. With the lower end portion of 44 as a fulcrum, it vibrates with a suspension length L ′. Thereby, since the starting end position of the suspension length can be substantially changed from the fixed portion on the ceiling side of the suspension member 42 to the position of the lower end portion of the small cylindrical body 44, the suspension system can be changed by changing the suspension length. The natural period can be changed. In addition, by adopting a configuration in which the small cylindrical body 44 is lowered from the ceiling side, it is possible to restrict vibration at a midway position of the suspension member 42 only when the natural period of the vibration system needs to be changed.

  The vibration restricting means to be lowered is not limited to the small cylindrical body 44, but may be a ring frame 46 as shown in FIG. 7, or an elastic body 47 made up of a plurality of cup-shaped members as shown in FIG. Also good.

[Fourth Embodiment]
Next, a vibration suppressing device according to the fourth embodiment will be described. The vibration suppression apparatus according to the fourth embodiment is the vibration suppression apparatus 1 according to the first embodiment in that the natural period changing mechanism 50 shown in FIG. 9 is applied as the natural period changing means in place of the winding device 5. The main difference.

  As shown in FIG. 9, the natural period changing mechanism 50 surrounds the suspension member 52 on the back side of the ceiling F and a fixing plate (fixing member) 53 fixed to the middle position of the suspension member 52 below the ceiling F. A ring frame 56 supported by the pillars 54, a ring 57 attached to be guided by the pillars 54 of the ring frame 56, and a plurality of auxiliary suspension members 58 connected to the ring 57 and the fixing plate 53. And a winding device (traction means) 59 that is disposed on the back side of the ceiling F and that pulls the auxiliary suspension material 58 at a midway position.

  The ring 57 attached to the column 54 is supported so as to be movable while being guided by the column 54 while being suspended from above by a spring or a strap. The auxiliary suspension member 58 has an upper end fixed to the ring 57, passes through the slit 61 of the ceiling F and is fixed to the fixing plate 53, and a midway position is connected to the winding device 59 via a wire. ing. Before the suspension length is changed, the auxiliary suspension member 58 is in a loose state, so that the fixing plate 53 can move in the horizontal direction. Therefore, as shown in FIG. 9, the suspended object 51 vibrates with a suspended length L with the fixed position on the ceiling side as a fulcrum.

  When changing the suspension length, the auxiliary suspension member 58 is tensioned by pulling the midway position of the auxiliary suspension member 58 with the winding device 59, as shown in FIG. At this time, since the fixed plate 53 receives tension from four directions by the tensioned auxiliary suspension member 58, movement in the horizontal direction is restricted. By restricting the movement of the fixed plate 53, the suspended object 51 can vibrate with the suspended length L ′ using the fixed plate 53 as a fulcrum. As described above, since the natural period changing mechanism 50 can change the starting end position of the suspension length from the fixed portion on the ceiling side of the suspension member 52 to the position of the stationary plate 53, the suspension length can be changed by changing the suspension length. The natural period can be changed.

[Fifth Embodiment]
Next, a vibration suppression device according to a fifth embodiment will be described. The vibration suppression device 70 according to the fifth embodiment is mainly different from the vibration suppression device 1 according to the first embodiment in that a control unit, a mechanical activation unit, a sensor, and the like are not used.

  As shown in FIG. 11, the vibration suppressing device 70 includes a large cylinder (vibration restricting means) 73 and a small cylinder (vibration restricting means) 74 arranged so as to surround the suspension material 72 on the back side of the ceiling F. . The large cylinder 73 and the small cylinder 74 are fixed to the upper wall surface of the structure together with the upper end of the suspension member 72, and the large cylinder 73 is longer than the small cylinder 74.

  According to such a vibration suppressing device 70, when the vibration of the suspended object 71 is small, as shown in FIG. 11 (a), the fixed to the upper wall surface without contacting the large cylinder 73 and the small cylinder 74. It vibrates at a suspension length L with the portion as a fulcrum. When the vibration increases, as shown in FIG. 11 (b), the suspended material 72 is regulated by the lower end of the small cylinder 74, so that the suspended object 71 is substantially positioned at the lower end of the small cylinder 74. Will be oscillated with a suspension length L ′. When the vibration further increases, as shown in FIG. 11C, the suspension material 72 is regulated by the lower end of the large cylinder 73, so that the suspended object 71 substantially positions the lower end of the large cylinder 73. As a fulcrum, it vibrates with a suspension length L ″. As described above, the start position of the suspension length can be changed from the fixed portion on the ceiling side of the suspension member 72 to the position of the lower end of the large cylinder 73 or the small cylinder 74 without providing a control unit or a mechanical activation device. Therefore, the natural period of the vibration system can be changed by automatically changing the suspension length.

  In place of the large cylinder 73 and the small cylinder 74, two ring frames 76 and 77 as shown in FIG.

[Sixth Embodiment]
Next, a vibration suppression device according to a sixth embodiment will be described. The vibration suppression device 80 according to the sixth embodiment is mainly different from the vibration suppression device 70 according to the fifth embodiment in that an elastic member is used instead of the cylindrical body.

  As shown in FIG. 13, the vibration suppression device 80 includes a rotation spring (elastic member) 83 that is disposed on the back side of the ceiling F and fixes the upper end of the suspension member 82. By connecting the rotary spring 83 to the suspension member, the substantial suspension length can be changed with a change in the centrifugal force acting on the suspension member 81. Specifically, when no vibration is generated, the hanging length of the suspended object 81 is L as shown in FIG. 13A, but when the vibration is generated, centrifugal force acts on the suspended object 81. As a result, the rotary spring 83 is extended, and the suspension length is L ′. When the vibration further increases, as shown in FIG. 13B, a larger centrifugal force acts on the suspended object 81 to increase the extension of the rotary spring 83, and the suspended length becomes L ″. As a result, the natural period of the vibration system can be automatically changed.

  The present invention is not limited to the embodiment described above.

  For example, in the embodiment described above, the control unit 7 evaluates the seismic wave characteristics, the vibration characteristics of the ground and the structure, and predicts the vibration of the suspended object. However, only one element may be evaluated. . Alternatively, when an emergency earthquake warning or initial tremor is detected, or when direct vibration is detected, the natural period may be changed immediately without performing the evaluation. Moreover, although the vibration is predicted based on both the earthquake early warning and the initial tremor, only one of them may be used.

  Furthermore, while the vibration prediction unit 11 predicts and controls the vibration and the vibration determination unit 12 directly detects and controls the vibration, only one of them may be used. Further, although the natural period changing means is both electrically activated and mechanically activated, only one of them may be used.

  Moreover, you may change the suspension length of a suspended object by combining suitably the natural period change mechanism of 1st Embodiment to 6th Embodiment.

It is a block diagram which shows the vibration suppression apparatus which concerns on the 1st Embodiment of this invention. It is a flowchart which shows the process which estimates and controls a vibration. It is a flowchart which shows the process which directly detects a vibration and performs control. It is the schematic which shows the vibration suppression apparatus which concerns on the 2nd Embodiment of this invention. It is a figure which shows the example of the midway position fixing | fixed part shown in FIG. It is the schematic which shows the vibration suppression apparatus which concerns on the 3rd Embodiment of this invention. It is a figure which shows the modification of the control means shown in FIG. It is a figure which shows the modification of the control means shown in FIG. It is the schematic which shows the vibration suppression apparatus which concerns on the 4th Embodiment of this invention. It is a figure which shows the mode after the suspension length change of the vibration suppression apparatus shown in FIG. It is the schematic which shows the vibration suppression apparatus which concerns on the 5th Embodiment of this invention. It is a figure which shows the modification of the control means shown in FIG. It is the schematic which shows the vibration suppression apparatus which concerns on the 6th Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1,70, ... Vibration suppression apparatus, 2, 21, 41, 51, 71, 81 ... Suspension, 3, 22, 42, 52, 72, 82 ... Suspension material, 4 ... Vibration system, 5 ... Winding device ( Natural period changing means), 7... Control unit (vibration predicting means, vibration detecting means, vibration determining means), 20, 40, 50... Natural frequency changing mechanism (natural frequency changing means), 24. Small cylindrical body (vibration restricting means) 46 ... Ring frame (vibration restricting means) 47 ... Stretchable body (vibration restricting means), 53 ... Fixed plate (fixing member), 58 ... Auxiliary suspension material, 59 ... Winding device (traction Means), 73, 74... Cylindrical body (vibration restricting means), 76, 77... Ring frame (vibration restricting means), 83.

Claims (14)

In the suspension vibration suppression device that suppresses the increase in horizontal vibration of the suspension suspended by a suspension material that can be bent at a long midway position in the structure,
By suppressing resonance between the natural period of the vibration system due to the suspension material and the suspended object and the natural period of the structure or the ground, an increase in horizontal vibration of the suspended object due to the shaking of the structure is suppressed. to, when the suspended material is vibrated, or when there is a possibility of vibration, by changing the hanging length of the hanging object, the vibration system constituted by the said suspended matter and the hanging member A vibration suppression apparatus comprising a natural period changing means for changing the natural period of the vibration.   The vibration suppressing device according to claim 1, further comprising vibration predicting means for predicting vibration of the suspended object and controlling the natural period changing means based on a prediction result.   The vibration suppressing device according to claim 2, wherein the vibration predicting unit predicts vibration of the suspended object based on an earthquake early warning.   The vibration suppressing device according to claim 2, wherein the vibration predicting unit predicts vibration of the suspended object based on an initial tremor of an earthquake.   The vibration suppression apparatus according to claim 2, wherein the prediction is performed based on a seismic wave characteristic of the earthquake.   The vibration suppressing device according to any one of claims 2 to 4, wherein the prediction is performed based on a vibration characteristic of the ground.   The vibration suppressing device according to claim 2, wherein the prediction is performed based on a vibration characteristic of the structure.   The vibration suppressing device according to claim 1, further comprising vibration detecting means for detecting vibration of the suspended object and controlling the natural period changing means based on a detection result.   9. The vibration suppression unit according to claim 8, wherein the vibration detection unit includes a vibration determination unit that determines whether or not the detected vibration increases and controls the natural period changing unit based on a determination result. apparatus.   10. The vibration suppression according to claim 1, wherein the natural period changing unit includes a midway position fixing unit that changes the suspension length by fixing a midway position of the suspension member. apparatus.   The said natural period change means has a vibration control means which controls the vibration of the horizontal direction of the said suspension material in the middle position of the said suspension material, The any one of Claims 1-9 characterized by the above-mentioned. Vibration suppression device.   The vibration suppressing device according to claim 11, wherein the vibration restricting unit descends from a ceiling side of the structure when the natural period of the vibration system is changed. The natural period changing means is
A fixing member fixed at an intermediate position of the suspension member;
A plurality of auxiliary suspension members having one end side connected to the fixing member;
It is connected to the other end side of the auxiliary suspension member, and when the natural period of the vibration system is changed, the fixing is performed by pulling the other end side of the auxiliary suspension member and tensioning the auxiliary suspension member. The vibration suppressing device according to claim 1, further comprising a pulling unit that restricts movement of the member in the horizontal direction.   The vibration suppressing device according to any one of claims 1 to 9, wherein the natural period changing means includes an elastic member connected to the suspension member.

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