JP2011220504A - Vibration suppressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vibration suppressor which even when a pre-tension given to a cable is relatively small, properly obtains a rotation inertia effect by a rotating mass during the vibration of a structure and suppresses the vibration of the structure through the rotation inertia effect.SOLUTION: In the vibration suppressor, a tension is given in advance to cables 31 and 31 connected to the structure 5, and the displacement of the structure 5 caused by the vibration of the structure 5 and transmitted through the cable 31 and 31 is transformed by a transforming mechanism into a rotational motion of a rotor. During the vibration of the structure 5, when a reaction force from a rotating mass that is generated as a result of transmission of a torque from the rotor to the rotating mass acts in a direction of increasing the tension of the cables 31 and 31, a transmission mechanism allows transmission of the torque from the rotor to the rotating mass. When the reaction force from the rotating mass acts in a direction of decreasing the tension of the cables 31 and 31, the transmission mechanism cuts off transmission of the torque from the rotor to the rotating mass.

Description

  The present invention relates to a vibration suppressing device for suppressing the vibration of a structure, and more particularly to a vibration suppressing device that uses a rotating mass to suppress the vibration of a structure.

  Conventionally, what was disclosed by patent document 1 as this kind of vibration suppression apparatus is known, for example. This vibration suppressing device is for suppressing the vibration of the beam, and includes a mass damper, an oblique member for transmitting the vibration of the beam to the mass damper, and an additional spring for applying tension to the oblique member. . The diagonal member is made of a steel wire and extends in the entire length direction of the beam, and one end portion and the other end portion thereof are fixed to one end portion and the other end portion of the beam, respectively. Moreover, both the mass damper and the additional spring are provided in parallel between the beam and the diagonal member. By this additional spring, the diagonal member is biased downward, so that tension is preliminarily applied (pre-tension) to the diagonal member. Furthermore, the mass damper is of the general type having a ball screw, a rotating mass and a viscous body.

  In the conventional vibration suppressing device having the above-described configuration, when the beam vibrates due to an earthquake or the like, the vibration of the beam is transmitted to the mass damper via the diagonal member, and is amplified and converted into the rotational motion of the rotating mass. Accordingly, the vibration of the beam is suppressed by obtaining the rotational inertia effect of the rotating mass and the viscous damping effect of the viscous body.

JP 2010-38318 A

  As described above, in this conventional vibration suppression device, the mass damper is provided between the beam and the diagonal member, and the diagonal member for transmitting the vibration of the beam to the mass damper is composed of a steel wire and added. Pretension is applied by being biased downward by a spring. For this reason, when the beam is bent downward by vibration, the mass damper is compressed, and the reaction force generated by the mass damper acts in the direction of increasing the tension of the diagonal member. Therefore, in this case, it is possible to transmit the vibration of the beam to the mass damper as a result of exerting the rigidity of the diagonal member.

  On the other hand, when the beam is bent upward due to vibration, the mass damper is extended, and the reaction force generated by the mass damper acts in a direction to reduce the tension of the diagonal member. In general, the mass damper has a characteristic that its reaction force is relatively large due to the configuration in which the relative displacement is amplified and converted into the rotational motion of the rotary mass. From the above, when the reaction force of the mass damper generated as the beam bends upward is larger than the biasing force of the additional spring, the diagonal member moves upward so as to follow the beam and loosens. Therefore, in this case, the rigidity of the diagonal member is not exhibited, and as a result, the vibration of the beam cannot be transmitted to the mass damper.

  After that, even if the beam bends downward due to vibration, because the diagonal material was loosened as described above, the diagonal material did not immediately return to the tension state and the rigidity of the diagonal material was not exhibited. The vibration of the beam cannot be transmitted to the mass damper. From the above, in this conventional vibration suppression device, when the beam is repeatedly bent up and down due to vibration, the vibration of the beam cannot be properly transmitted to the mass damper, so that the vibration damping effect by the mass damper cannot be obtained. There is a possibility that the vibration of the can not be suppressed.

  In addition, in order to prevent such a problem, in order to hold the diagonal member in tension during the vibration of the beam, an additional spring having a higher urging force than the mass damper reaction force should be used. ,Conceivable. However, in that case, excessive pretension always acts on the diagonal member, resulting in excessive long-term axial force (prestress) of the beam. In this case, the additional spring and the mass damper are provided in parallel to the diagonal member, and the rotational inertia effect of the rotary mass of the mass damper is suppressed due to the rigidity of the additional spring being too high. There is a problem that the damping effect by the mass damper cannot be obtained properly.

  The present invention has been made to solve the above-described problems, and even when the pretension applied to the cable is relatively small, the rotational inertia effect of the rotating mass is appropriately obtained during the vibration of the structure. An object of the present invention is to provide a vibration suppressing device that can suppress vibrations of a structure.

  In order to achieve the above object, an invention according to claim 1 is a vibration suppressing device for suppressing vibration of a structure, wherein a tension is applied in advance and a cable connected to the structure; A conversion mechanism that has a rotating body, is connected to the cable, is generated by vibration of the structure, and is transmitted through the cable, and converts the displacement of the structure into a rotational motion of the rotating body; and a rotatable rotating mass; The reaction force from the rotating mass generated by the transmission of the rotational force from the rotating body to the rotating mass during the vibration of the structure acts in the direction of increasing the cable tension. Sometimes, the transmission of the rotational force from the rotating body to the rotating mass is allowed, and when the reaction force from the rotating mass acts in the direction of reducing the cable tension, the rotating body rotates to the rotating mass. Characterized in that it comprises a transmission mechanism for blocking the transmission.

  According to this configuration, tension is preliminarily applied (pretension) to the cable coupled to the structure, and the conversion mechanism is connected to the cable. The displacement of the structure generated by the vibration of the structure is transmitted to the conversion mechanism via the cable, and the conversion mechanism converts the transmitted displacement of the structure into the rotational motion of the rotating body. The transmission mechanism is connected to the rotating body and the rotating mass, and the rotational force of the rotating body is transmitted to the rotating mass by the transmitting mechanism.

  Specifically, during vibration of the structure, when the reaction force from the rotating mass generated along with the transmission of the rotating force from the rotating body to the rotating mass acts in the direction of increasing the cable tension, that is, the cable When the rigidity of the rotor is reliably exhibited, transmission of the rotational force from the rotating body to the rotating mass is allowed by the transmission mechanism. Thereby, the displacement of the structure generated by the vibration of the structure and transmitted to the conversion mechanism is converted into the rotational motion of the rotary mass, and the rotary mass rotates. Due to the rotational inertia effect of the rotating mass, the apparent mass (equivalent mass) of the rotating mass is amplified with respect to the actual mass (substantial amount), thereby suppressing the vibration of the structure.

  In addition, when the reaction force from the rotating mass generated by the transmission of the rotating force from the rotating body to the rotating mass acts in the direction of reducing the cable tension during the vibration of the structure, the reaction from the rotating mass is reduced. When the force is larger than the pre-tension of the cable, there is a possibility that the cable is loosened and its rigidity is not exhibited as in the conventional case described above. According to the above-described configuration, in such a case, transmission of the rotational force from the rotating body to the rotating mass is blocked by the transmission mechanism, so that the reaction force from the rotating mass does not act on the cable. Will not loosen.

  Therefore, even when the pretension applied to the cable is relatively small, the cable can always be held in tension during the vibration of the structure, so that the displacement of the structure is appropriately transmitted to the conversion mechanism via the cable. It can be appropriately converted into the rotational motion of the rotating mass. Therefore, the rotational inertia effect of the rotary mass described above can be appropriately obtained, and thereby vibration of the structure can be suppressed. For the same reason, since the pretension applied to the cable can be made relatively small, the prestress of the structure can be suppressed. In addition, as in the conventional case described above, when the cable is tensioned by the additional spring and the additional spring and the conversion mechanism are provided in parallel with the cable, the biasing force of the additional spring is reduced, Since the rigidity can be lowered, it is possible to prevent the rotational inertia effect of the rotary mass from being suppressed due to the influence of the additional spring.

  The invention according to claim 2 is the vibration suppressing device according to claim 1, wherein the vibration suppressing device is composed of a pair of vibration suppressing devices each including a cable, a conversion mechanism, a rotating mass, and a transmission mechanism. When the reaction force from one rotating mass of the pair of vibration suppressing devices acts in a direction to reduce the tension of one cable during the vibration of the pair, the reaction force from the other rotating mass of the pair of vibration suppressing devices is When the reaction force from the other rotating mass acts in the direction to increase the tension of the cable and the direction to reduce the tension of the other cable, the reaction force from one rotating mass exerts the tension on one cable. It is configured to act in the increasing direction.

  According to this configuration, the vibration suppressing device includes a pair of vibration suppressing devices each including the cable, the conversion mechanism, the rotating mass, and the transmission mechanism described in the description of claim 1. Further, during the vibration of the structure, the reaction force from one rotating mass of the pair of vibration suppressing devices acts in a direction to reduce the tension of the one cable, so that the one rotating mass is moved from the one rotating body. When the transmission of the rotational force to is interrupted, the reaction force from the other rotational mass of the pair of vibration suppression devices acts in the direction of increasing the tension of the other cable, thereby causing the other rotational body to Transmission of rotational force to the other rotational mass is allowed.

  Conversely, the reaction force from the other rotating mass acts in the direction of reducing the tension of the other cable, so that the transmission of the rotating force from the other rotating body to the other rotating mass is blocked. In some cases, reaction force from the one rotating mass acts in a direction to increase the tension of the one cable, thereby permitting transmission of torque from the one rotating body to the one rotating mass. As described above, the rotational inertia effect of the other rotary mass can be obtained when the rotational inertia effect of the other rotary mass cannot be obtained, and the rotational inertia effect of the other rotary mass can be obtained when the rotary inertia effect of the other rotary mass cannot be obtained. Since the rotational inertia effect can be obtained, the vibration of the structure can be suppressed quickly and sufficiently.

  The invention according to claim 3 is the vibration suppressing device according to claim 1 or 2, wherein the conversion mechanism has a screw shaft connected to the cable, and the screw shaft transmits the displacement of the structure via the cable. Accordingly, the rotary body is configured to reciprocate in the axial direction of the screw shaft, and the rotating body is screwed into the screw shaft via a ball, and the reciprocating motion in the axial direction of the screw shaft is rotationally moved. The conversion mechanism further includes a guide for guiding the reciprocation of the screw shaft in the axial direction so that the screw shaft does not rotate.

  According to this configuration, the screw shaft of the conversion mechanism is connected to the cable, and the screw shaft moves in the axial direction as the displacement generated by the vibration of the structure is transmitted through the cable. It is configured to reciprocate. The rotating body is formed of a nut that is screwed onto the screw shaft via a ball, and converts the reciprocating movement of the screw shaft in the axial direction into a rotational motion.

  Thus, since the conversion mechanism is configured by a so-called ball screw, when the reciprocating movement of the screw shaft is converted into the rotational motion of the nut as described above, a reaction torque acts from the nut to the screw shaft, Thereby, the screw shaft rotates, and as a result, the cable connected to the screw shaft may be twisted. According to the above-described configuration, the guide guides the reciprocating movement of the screw shaft in the axial direction so that the screw shaft does not rotate. Therefore, the twisting of the cable as described above can be prevented, and therefore the vibration of the structure causes The displacement can be converted into the rotational motion of the rotary mass without waste.

  The invention according to claim 4 is the vibration suppressing device according to claim 3, wherein the transmission mechanism is a one-way clutch.

  As described in the description of claim 3, the displacement of the structure transmitted to the conversion mechanism is converted into the reciprocating movement of the screw shaft, and then converted into the rotational motion of the nut. For this reason, the rotational directions of the nut when the screw shaft enters and retreats by this reciprocation are opposite to each other.

  According to the above-described configuration, since the one-way clutch that transmits power only in a certain direction is used as the transmission mechanism, the rotational force from the nut to the rotary mass when the screw shaft enters (or retracts) from the nut. In contrast to this, when retreating (or entering), transmission of rotational force to the rotating mass can be interrupted. Thereby, only when the action described in the description of claim 1, that is, when the reaction force from the rotating mass acts in the direction of increasing the tension of the cable, the transmission of the rotating force from the rotating body to the rotating mass is allowed. The action can be realized.

  Moreover, since a general one-way clutch is used as the transmission mechanism, the vibration suppressing device can be configured easily and inexpensively without preparing a special mechanism.

  The invention according to claim 5 is the vibration suppressing device according to any one of claims 1 to 4, further comprising a damping element for damping the rotation of the rotating mass.

  According to this configuration, the damping effect of the damping element can be obtained in addition to the rotational inertia effect of the rotating mass. In addition, during the vibration of the structure, the rotating mass rotated by the transmission of the displacement of the structure is not rotated by inertia, but the rotation is attenuated by the damping element, so that the structure that is repeatedly transmitted to the conversion mechanism The rotational inertia effect of the rotary mass can be appropriately obtained in accordance with the displacement of. As described above, the vibration of the structure can be further appropriately suppressed.

It is a figure which shows roughly the 1st vibration suppression apparatus among the vibration suppression apparatuses by 1st Embodiment of this invention with the bridge to which this is applied. It is an enlarged view of the 1st vibration suppression apparatus etc. which are shown in FIG. It is a figure which shows roughly the 2nd vibration suppression apparatus among the vibration suppression apparatuses by 1st Embodiment of this invention with the bridge to which this is applied. FIG. 4 is an enlarged view of a second vibration suppressing device shown in FIG. 3. It is a perspective view of the mass damper shown in FIGS. It is a figure for demonstrating the characteristic of the mass damper shown in FIG. It is another figure for demonstrating the characteristic of the mass damper shown in FIG. FIG. 6 is a diagram illustrating a relationship between a frequency ratio and a displacement response magnification when the mass damper illustrated in FIG. 5 is applied to a structure. It is a figure which respectively shows the model of the 1st vibration suppression apparatus shown in FIG. 1 about (a) during compression of a mass damper, (b) During expansion of a mass damper. It is a figure which shows roughly the vibration suppression apparatus by 2nd Embodiment of this invention with the building to which this is applied. It is a figure which shows roughly the vibration suppression apparatus by 3rd Embodiment of this invention with the building to which this is applied.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. The vibration suppression device according to the first embodiment of the present invention is composed of a pair of vibration suppression devices including a first vibration suppression device 1 and a second vibration suppression device 2 shown in FIGS. 1 and 3, respectively. This is to suppress the vibration of the generated bridge 5. This bridge 5 is made of H-shaped steel, is supported by a plurality of piers 6, 6,... (Only two are shown), and extends horizontally. The first vibration suppression device 1 is provided on one side surface of the bridge 5, and the second vibration suppression device 2 is provided on the other side surface of the bridge 5.

  As shown in FIGS. 1 and 2, the first vibration suppression device 1 includes a mass damper 11 and a pair of cables 31 and 31 for transmitting displacement (vibration) of the bridge 5 caused by an earthquake or the like to the mass damper 11. ing. These cables 31, 31 are made of, for example, steel wires, and are connected to each other by connecting one end of the cable 31 to the connecting portion 32, and in the longitudinal direction of the bridge 5, the connecting portion 32 is the center. It is provided symmetrically. The other end of one cable 31 is fixed to the upper part of a portion of the bridge 5 that is supported by one of the two adjacent piers 6, and the other end of the other cable 31 is connected to the bridge. 5 is fixed to the upper part of the portion supported by the other pier 6.

  As shown in FIG. 5, the mass damper 11 includes an outer cylinder 12, a ball screw 13, a guide 17, a rotating mass 18, a one-way clutch 19, and a viscous body 20, and a vibration suppressing effect only when compressed. It is configured as a one-effect one that can be obtained.

  The ball screw 13 includes a screw shaft 14 and a nut 16 that is screwed onto the screw shaft 14 via a large number of balls 15, and is concentrically provided on the outer cylinder 12. In FIG. 5, for convenience, some reference numerals of a plurality of components such as the ball 15 are omitted. The screw shaft 14 is formed with a screw groove 14a with which the ball 15 is engaged and a spline groove 14b extending in the axial direction. The width of the spline groove 14b is set to a value larger than the width of the screw groove 14a. Has been. The nut 16 is housed in the outer cylinder 12 and is rotatable with respect to the outer cylinder 12 and cannot move in the axial direction by the pair of first radial bearings RB1 and RB1 and the thrust bearings TB and TB. It is supported and is located at one end of the outer cylinder 12 in the axial direction. Further, a part of the screw shaft 14 protrudes outward from the outer cylinder 12, and can reciprocate a predetermined distance in the axial direction with respect to the outer cylinder 12.

  In the ball screw 13 having the above configuration, when the screw shaft 14 reciprocates in the axial direction by an external force, the nut 16 rotates around the axis along with the reciprocation. That is, the reciprocating movement of the screw shaft 14 is converted into the rotational movement of the nut 16.

  The guide 17 has a cylindrical shape having a guide hole 17a and is concentrically fixed to an end portion of the outer cylinder 12 on the screw shaft 14 side. A screw shaft 14 is inserted into the guide hole 17a. Further, a plurality of balls 17 b are provided on the inner peripheral surface of the guide 17. Each ball 17b is set to have a diameter that is larger than the width of the thread groove 14a of the screw shaft 14 and slightly smaller than the width of the spline groove 14b. Further, half of the ball 17b is engaged with a hemispherical groove 17c formed on the inner peripheral surface of the guide 17, and the other half is engaged with the spline groove 14b. , 14b.

  In the guide 17 and the screw shaft 14 configured as described above, when the screw shaft 14 reciprocates in the axial direction with respect to the nut 16, the ball 17 b moves on the spline groove 14 b without moving in the circumferential direction with respect to the guide 17. Thus, the screw shaft 14 is reciprocated without trouble. Further, due to the configuration of the ball screw 13, reaction torque acts from the nut 16 to the screw shaft 14 as the screw shaft 14 reciprocates with respect to the nut 16. On the other hand, since the ball 17b is engaged with the hemispherical groove 17c of the guide 17 fixed to the outer cylinder 12 and the spline groove 14b extending in the axial direction of the screw shaft 14, such reaction force is generated. Even if the torque acts on the screw shaft 14, the rotation of the screw shaft 14 with respect to the outer cylinder 12 is prevented. In this way, the reciprocating movement of the screw shaft 14 is guided by the guide 17 so as not to rotate the screw shaft 14.

  The rotating mass 18 is made of a material having a large specific gravity, such as iron, and is formed in a cylindrical shape. Further, the rotating mass 18 is accommodated in a portion of the outer cylinder 12 opposite to the nut 16 of the ball screw 13 and is arranged coaxially with the nut 16. A second rotating body 19b (to be described later) of the one-way clutch 19 is fixed to the rotating mass 18 in a coaxial manner. The rotating mass 18 and the second rotating body 19b are rotatably supported with respect to the outer cylinder 12 by a pair of second radial bearings RB2 and RB2, and are rotatable together.

  The one-way clutch 19 is of a general ratchet type and has a first rotating body 19a and a second rotating body 19b. The first rotating body 19 a is fixed coaxially to the nut 16 and is rotatable integrally with the nut 16. The second rotating body 19b is provided with a claw (not shown).

  In the one-way clutch 19 having the above-described configuration, as the screw shaft 14 moves in the direction of entering the outer cylinder 12 while the rotating mass 18 is stopped, the nut 16 and the first rotating body 19a are moved to the direction of the arrow shown in FIG. When a torque that rotates in the direction acts, the claw engages with the first rotating body 19a, thereby connecting between the first rotating body 19a and the second rotating body 19b. The bodies 19a and 19b rotate together. Thereby, in this case, the rotational force is transmitted from the nut 16 to the rotary mass 18 via the one-way clutch 19.

  On the other hand, when the screw shaft 14 moves in the direction projecting from the outer cylinder 12, when the torque in the direction opposite to the arrow shown in FIG. 5 acts on the nut 16 and the first rotating body 19a, the claw rotates first. As a result of the disconnection between the first rotating body 19a and the second rotating body 19b, the torque is not transmitted from the first rotating body 19a to the second rotating body 19b. Thereby, in this case, the rotational force from the nut 16 is not transmitted to the rotary mass 18 via the one-way clutch 19, and the nut 16 and the first rotating body 19a are idled.

  The viscous body 20 is made of silicon oil or the like and is filled between the outer cylinder 12 and the rotating mass 18. The outer cylinder 12 is provided with a packing (not shown) for preventing the viscous body 20 from leaking.

  Next, the characteristics of the mass damper 11 having the above configuration will be described with reference to FIGS. FIG. 6A shows that the damping force (hereinafter referred to as “viscous body damping force”) DF acting on the outer cylinder 12 and the screw shaft 14 is assumed to have a value of 0, and is input to the mass damper 11. And a rotational inertia force (hereinafter referred to as “rotational mass inertial force”) IF of the rotary mass 18 acting on the outer cylinder 12 and the screw shaft 14. FIG. 6B shows the relationship between the inter-node displacement Dis and the viscous body damping force DF when the rotational mass inertial force IF is assumed to be 0. Further, FIG. 6C shows the relationship between the inter-node displacement Dis and the reaction force of the mass damper 11 (hereinafter referred to as “mass damper reaction force”) RF. FIG. 7 shows transitions of the internode displacement Dis, the internode velocity Vel, and the internode acceleration Acc. 6 and 7 show various parameters when a standing wave is input as the inter-node displacement Dis.

  6A to 6C, point a is when the screw shaft 14 starts to move toward the outer cylinder 12 from the projecting position where the screw shaft 14 protrudes most from the outer cylinder 12, that is, the mass damper 11 is fully extended. The point c represents the relationship when the screw shaft 14 is positioned at the entry position where it has entered the outer cylinder 12 most, that is, when the mass damper 11 has been fully contracted. . Further, the point b is when the screw shaft 14 moves from the protruding position to the entering position and is located at a neutral position between the protruding position and the entering position, that is, the mass damper 11 is in the compression neutral state. The point d represents the relationship when the screw shaft 14 is positioned from the entry position to the neutral position, that is, when the mass damper 11 is in the extension neutral state. Furthermore, the point e represents the relationship when the screw shaft 14 is located at the protruding position, that is, when the mass damper 11 is fully extended.

  Further, in FIG. 7, the time point ta corresponds to the timing when the mass damper 11 starts to contract from the fully extended state, and the time point tb corresponds to the timing when the mass damper 11 enters the compression neutral state. Further, the time point tc corresponds to a timing when the mass damper 11 is fully contracted, and the time point td corresponds to a timing when the mass damper 11 is in the above-described extension neutral state. Furthermore, the time point te corresponds to the timing when the mass damper 11 is fully extended. As described above, the points in time ta, tb, tc, td, and te in FIG. 7 correspond to the points a, b, c, d, and e in FIG. 6, respectively. Further, the locus from point a to point b and point c in FIG. 6 represents the relationship when the mass damper 11 is compressed, and the locus from point c to point d and point e is expanded by the mass damper 11. Represents the relationship when being done. Similarly, the transition of various parameters during the compression of the mass damper 11 is represented from the time ta to the time tc in FIG. 7, and the various parameters during the expansion of the mass damper 11 are represented from the time tc to the time te. It shows the transition of parameters.

  As shown in FIG. 7, the internode displacement Dis, the internode velocity Vel, and the internode acceleration Acc input to the mass damper 11 change in a sine wave shape, and the internode displacement Dis and the internode velocity Vel are 90 ° in phase with each other. The phases of the inter-node displacement Dis and the inter-node acceleration Acc are 180 degrees out of phase with each other. Further, the inter-node displacement Dis has a negative maximum value −DM at the time points ta and te, has a value of 0 at the time points tb and td, and has a positive maximum value + DM at the time point tc. Further, the inter-node velocity Vel is 0 at the time points ta, tc, and te, and has a positive maximum value at the time point tb and a negative maximum value at the time point td. Further, the internode acceleration Acc has a positive maximum value at the time points ta and te, has a value of 0 at the time points tb and td, and has a negative maximum value at the time point tc.

  As described above, the rotational force is transmitted from the nut 16 to the rotary mass 18 via the one-way clutch 19. Basically, when the screw shaft 14 moves toward the outer cylinder 12, that is, when the mass damper 11 is compressed, a rotational force is transmitted from the nut 16 to the rotary mass 18, while the mass damper 11 is being extended. In this case, no rotational force is transmitted from the nut 16 to the rotary mass 18. Further, the rotational mass inertia force IF depends on the internode acceleration Acc, and becomes larger as the internode acceleration Acc is higher.

  From the above, when it is assumed that the viscous body damping force DF has a value of 0, the rotational mass inertia force IF changes as shown in FIG. 6A according to the inter-node displacement Dis. That is, when the mass damper 11 starts to contract from the state where the inter-node displacement Dis becomes the negative maximum value −DM (the state where the mass damper 11 is fully extended) (time point ta), the inter-node acceleration Acc is shown in FIG. Thus, the rotational mass inertia force IF becomes maximum as shown by a point a in FIG. Further, the smaller the absolute value of the internode displacement Dis, which is a negative value, that is, the more the mass damper 11 is contracted, the lower the acceleration Acc between the nodes, and thus the rotational mass inertial force IF becomes smaller.

  When the inter-node displacement Dis becomes 0 (time point tb), that is, when the mass damper 11 is in a compression neutral state, the inter-node acceleration Acc becomes 0, so that the rotational mass inertial force IF becomes a value. 0 (point b). Further, during the subsequent compression of the mass damper 11 (to time tc), the rotational speed of the rotary mass 18 exceeds the rotational speed of the nut 16, so that the one-way clutch 19 blocks the nut 16 and the rotary mass 18. The rotation mass inertia force IF becomes 0 (˜point c). Further, during the expansion of the mass damper 11 (to time td to time te), the rotational force is not transmitted from the nut 16 to the rotating mass 18 due to the interruption between the nut 16 and the rotating mass 18 by the one-way clutch 19, so The rotational mass inertial force IF becomes zero until the inter-node displacement Dis again reaches the negative maximum value −DM, that is, until immediately before the mass damper 11 starts to contract (˜point d to point e). .

  In addition, the viscous body damping force DF depends on the internode velocity Vel, and increases as the internode velocity Vel increases. Since this and the transmission of the rotational force between the nut 16 and the rotary mass 18 are performed as described above, the viscous body damping force DF is assumed when the rotary mass inertia force IF is zero. According to the inter-node displacement Dis, it changes as shown in FIG. That is, when the mass damper 11 starts to contract from the state in which the inter-node displacement Dis becomes the negative maximum value −DM (time point ta), the inter-node velocity Vel becomes a value 0 as shown in FIG. The viscous body damping force DF has a value of 0 as indicated by a point a in FIG. Then, as the absolute value of the internode displacement Dis, which is a negative value, decreases, that is, as the mass damper 11 contracts, the velocity Vel between the nodes increases, so that the viscous body damping force DF increases, and the internode displacement Dis becomes smaller. When the value becomes 0 (time point tb), that is, when the mass damper 11 enters the compression neutral state, the maximum value is reached (point b).

  Further, as the positive internode displacement Dis becomes larger, that is, as the mass damper 11 further shrinks, the internode velocity Vel decreases, so that the viscous body damping force DF becomes smaller and the internode displacement Dis becomes positive. When the maximum value + DM is reached (time point tc), that is, when the mass damper 11 is fully contracted, the value becomes 0 (point c). Further, during the extension of the mass damper 11 (to time td to time te), the shearing force does not act on the viscous body 20 from the nut 16 due to the disconnection between the nut 16 and the rotary mass 18 by the one-way clutch 19. The viscous body damping force DF has a value of 0 until the inter-node displacement Dis again reaches the negative maximum value −DM, that is, until just before the mass damper 11 starts to contract (˜point d to point e).

  From the above, the mass damper reaction force RF by the mass damper 11 that generates both the rotary mass inertia force IF and the viscous body damping force DF changes as shown in FIG. 6C according to the inter-node displacement Dis. That is, when the mass damper 11 starts to shrink from a state in which the inter-node displacement Dis becomes the negative maximum value −DM, the mass damper reaction force RF becomes equal to the rotational mass inertia force IF shown in FIG. ). In the initial stage after the compression of the mass damper 11 is started, the mass damper reaction force RF becomes larger as the absolute value of the negative internode displacement Dis becomes smaller (as the mass damper 11 contracts). Thereafter, as the mass damper 11 is further contracted, the mass damper reaction force RF becomes smaller, and immediately before the inter-node displacement Dis becomes the positive maximum value + DM (a straight line in which the mass damper 11 fully contracts), the rotational speed of the rotary mass 18 is the nut. When the rotational speed of 16 is exceeded, the space between the nut 16 and the rotary mass 18 is blocked by the one-way clutch 19, so that the rotary mass reaction force RF becomes zero. Thereafter, until the inter-node displacement Dis again reaches the negative maximum value −DM, that is, until just before the mass damper 11 is fully extended and starts to contract again (point c to point d to point e), the mass damper is The reaction force RF is zero.

  As described above, the mass damper reaction force RF is obtained only during compression of the mass damper 11 and assumes a value of 0 during expansion. That is, the mass damper 11 is configured as a one-sided effect that provides a vibration suppressing effect only during compression.

  As shown in FIG. 2, the outer cylinder 12 of the mass damper 11 is integrally provided with a connecting member 21 at the end opposite to the screw shaft 14, and this connecting member 21 is a flange for mounting. 22 is rotatably connected. Further, a spring seat 23 is attached to the screw shaft 14 at the end opposite to the nut 16. A tension spring 24 is provided between the spring seat 23 and the outer cylinder 12, and the tension spring 24 is composed of a compression coil spring.

  The mass damper 11 having the above configuration is fixed to the bridge 5 by the flange 22 being attached to the upper end portion of the bridge 5 via the fixture 33, and the spring seat 23 is rotatable to the connecting portion 32 described above. By being attached, the cables 31 and 31 are connected. In this state, the mass damper 11 is in a neutral state that is not expanded and contracted, and is located at the center of the bridge 5 between the two adjacent piers 6 and 6. The cables 31 and 31 are urged downward by the urging force of the tension spring 24 acting via the spring seat 23 and the connecting portion 32. As a result, tension is applied to the cables 31 and 31 in advance (pre-tension), and pre-stress is applied to the bridge 5.

  In the first vibration suppression device 1 and the bridge 5 configured as described above, as shown by a two-dot chain line in FIG. 1, when the bridge 5 is bent downward by the vibration of the primary mode, the bending of the bridge 5, that is, the displacement of the bridge 5 is reduced. Then, it is transmitted to the mass damper 11 via the cables 31 and 31. Thereby, as a result of compressing the mass damper 11, the vibration suppression effect by the mass damper reaction force RF is obtained. In this case, the mass damper reaction force RF acts in a direction to increase the tension of the cables 31 and 31.

  FIG. 8A shows a model of the first vibration suppression device 1 when the bridge 5 is bent downward due to the vibration of the primary mode. Symbols mi, cd, KT, and kb in the figure represent the mass of the rotating mass 18, the viscosity coefficient of the viscous body 20, the spring constant of the tension spring 24, and the rigidity of the cables 31, 31, respectively. As is apparent from FIG. 8A, in this case, the bridge 5 receives a resultant force composed of the mass damper reaction force RF composed of the rotational mass inertial force IF and the viscous body damping force DF and the reaction force of the tension spring 24. , 31 and the resultant force act on the bridge 5. Therefore, the vibration suppression effect by the vibration suppression device 1 is achieved by synchronizing the natural frequency of the additional vibration system including the rotary mass 18, the viscous body 20, the tension spring 24 and the cables 31 and 31 with the natural frequency of the bridge 5. You can get it properly.

  On the other hand, as shown by a one-dot chain line in FIG. 1, when the bridge 5 is bent upward by the vibration of the primary mode, the displacement of the bridge 5 is transmitted to the mass damper 11 via the cables 31 and 31. Due to this and the urging force of the tension spring 24 acting, the mass damper 11 is extended. In this case, if a mass damper reaction force RF is generated, the mass damper reaction force RF acts in a direction to reduce the tension of the cables 31 and 31. On the other hand, since the mass damper reaction force RF becomes 0 while the mass damper 11 is extended as described above, the cables 31 and 31 move upward following the bridge 5 due to the influence of the mass damper reaction force RF, Accordingly, the tension spring 24 does not loosen and is held in tension.

  FIG. 8B shows a model of the first vibration suppression device 1 when the bridge 5 is bent upward due to the vibration of the primary mode. As can be seen from the figure, in this case, the mass damper reaction force RF composed of the rotary mass inertia force IF and the viscous body damping force DF does not act on the bridge 5, but only the reaction force by the tension spring 24 and the cables 31 and 31. Act.

  Further, the mass mi of the rotary mass 18 of the first vibration suppressing device 1, the viscosity coefficient cd of the viscous body 20, the spring constant KT of the tension spring 24, and the rigidity kb of the cables 31, 31 are the above-described additional vibration system (rotary mass). 18, the natural frequency of the viscous body 20, the tension spring 24, and the cables 31, 31) is set to a value that synchronizes with the natural frequency of the primary mode of the bridge 5.

  FIG. 9 shows the relationship between the frequency ratio p / ωs and the displacement response magnification u / ug in the bridge 5 to which the first vibration suppression device 1 is applied. Here, ωs is the natural circular frequency of the bridge 5, and p is the excitation circular frequency of the ground supporting the bridge 5. Further, ug is a displacement input to the bridge 5 from the ground, and u is a relative response displacement of the bridge 5 from the ground. Further, the solid line and the alternate long and short dash line in FIG. 9 indicate the mass damper 11 during compression and expansion, respectively. As shown in the figure, during the compression of the mass damper 11, the displacement response magnification u / ug is a relatively small value due to the vibration suppression effect by the mass damper reaction force RF and the tuning of the natural frequency of the additional vibration system with respect to the bridge 5. It can be seen that the vibration suppression effect of the first vibration suppression device 1 can be appropriately obtained.

  As shown in FIGS. 3 and 4, the second vibration suppression device 2 includes the mass damper 11 and the cables 31, 31, similarly to the first vibration suppression device 1, and these mass damper 11 and the cables 31, 31. Is different from the mass damper 11 of the first vibration suppressing device 1 and the cables 31 and 31 only in that it is attached to the bridge 5 upside down. Specifically, the mass damper 11 of the second vibration suppression device 2 is fixed to the bridge 5 by the flange 22 being attached to the lower end portion of the bridge 5 via the fixture 33.

  The other end of one cable 31 of the second vibration suppressing device 2 is fixed to a lower portion of a portion of the bridge 5 that is supported by one of the two adjacent piers 6, and the other cable 31. Is fixed to the lower part of the portion of the bridge 5 supported by the other pier 6. Furthermore, the cables 31 and 31 are biased upward by the biasing force of the tension spring 24 acting via the spring seat 23 and the connecting portion 32. Thus, pretension is applied to the cables 31 and 31 and prestress is applied to the bridge 5.

  In the second vibration suppressing device 2 and the bridge 5 having the above-described configuration, as shown by a one-dot chain line in FIG. 3, when the bridge 5 is bent upward due to the vibration of the primary mode, the mass damper 11 is compressed as a result. The vibration suppression effect by the reaction force RF can be obtained. In this case, the mass damper reaction force RF acts in a direction to increase the tension of the cables 31 and 31. The model of the second vibration suppression device 2 in this case is shown in the same manner as in FIG.

  On the other hand, as shown by a two-dot chain line in FIG. 3, when the bridge 5 is bent downward by the vibration of the primary mode, the mass damper 11 is expanded due to this and the urging force of the tension spring 24 acting. . In this case, if a mass damper reaction force RF is generated, the mass damper reaction force RF acts in a direction to reduce the tension of the cables 31 and 31. On the other hand, in the second vibration suppression device 2, the mass damper reaction force RF becomes 0 during the expansion of the mass damper 11, as in the first vibration suppression device 1, so that the cables 31 and 31 are affected by the mass damper reaction force RF. Therefore, it does not move downward following the bridge 5 and does not loosen thereby, and is held in tension by the tension spring 24. Moreover, the model of the 2nd vibration suppression apparatus 2 in this case is shown similarly to FIG.8 (b).

  As described above, the first and second vibration suppressing devices 1 and 2 can obtain the vibration suppressing effect by the other when the vibration suppressing effect by one is not properly obtained, and the vibration suppressing effect by the other is appropriately obtained. When it cannot be obtained, the vibration suppressing effect by one can be obtained.

  Further, the mass mi of the rotary mass 18 of the second vibration suppression device 2, the viscosity coefficient cd of the viscous body 20, the spring constant KT of the tension spring 24, and the rigidity kb of the cables 31 and 31 are the same as those of the first vibration suppression device 1. The natural frequency of the additional vibration system (the rotary mass 18, the viscous body 20, the tension spring 24, and the cables 31, 31) is set to a value that synchronizes with the natural frequency of the primary mode of the bridge 5.

  As described above, according to the first embodiment, the displacement (deflection) of the bridge 5 caused by the vibration of the bridge 5 is transmitted to the ball screw 13 via the cables 31 and 31 to which pretension is applied. At the same time, the transmitted displacement of the bridge 5 is converted into the rotational motion of the nut 16. Further, the rotational force of the nut 16 is transmitted to the rotary mass 18 by the one-way clutch 19 as follows.

  That is, during the vibration of the bridge 5, the mass damper reaction force RF including the rotational mass inertial force IF generated along with the transmission of the rotational force from the nut 16 to the rotational mass 18 acts in the direction of increasing the tension of the cables 31 and 31. When doing so, transmission of the rotational force from the nut 16 to the rotary mass 18 is permitted by the one-way clutch 19. On the contrary, when the mass damper reaction force RF generated along with the transmission of the rotational force from the nut 16 to the rotary mass 18 acts in a direction to reduce the tension of the cables 31, 31, the rotation from the nut 16 to the rotary mass 18. The transmission of force is interrupted by the one-way clutch 19.

  Therefore, even when the pretension applied to the cables 31 and 31 is relatively small, the cables 31 and 31 can always be held in tension during the vibration of the bridge 5, so that the displacement of the bridge 5 Therefore, it can be appropriately transmitted to the ball screw 13 and converted into the rotational motion of the rotary mass 18. Therefore, it is possible to appropriately obtain the vibration suppression effect by the mass damper reaction force RF that combines the rotary mass inertia force IF, that is, the rotary inertia effect of the rotary mass 18 and the viscous body damping force DF, that is, the viscous damping effect of the viscous body 20. In addition, the vibration of the bridge 5 can be appropriately suppressed by synchronizing the natural frequency of the additional vibration system with respect to the bridge 5. For the same reason, the biasing force of the tension spring 24 that applies pre-tension to the cables 31 and 31 can be made relatively small, so that the pre-stress of the bridge 5 can be suppressed and the rigidity of the tension spring 24 is reduced. This also makes it possible to more appropriately obtain the vibration suppression effect of the vibration suppression device.

  Further, during the vibration of the bridge 5, one mass damper reaction force RF of the first and second vibration suppressing devices 1, 2 acts in a direction to reduce the tension of the one cable 31, 31, thereby When the transmission of the rotational force from the nut 16 to the one rotary mass 18 is interrupted, the other mass damper reaction force RF of the first and second vibration suppression devices 1 and 2 increases the tension of the other cables 31 and 31. Acting in the increasing direction, the transmission of rotational force from the other nut 16 to the other rotating mass 18 is allowed. As described above, since the vibration suppressing effect by any one of the first and second vibration suppressing devices 1 and 2 can always be obtained, the vibration of the bridge 5 can be quickly and sufficiently suppressed.

  Further, since the guide 17 guides the reciprocating movement of the screw shaft 14 in the axial direction so that the screw shaft 14 does not rotate, it is possible to prevent the cables 31 and 31 from being twisted. It is possible to convert the rotational mass 18 into a rotational motion without waste. Furthermore, since the general one-way clutch 19 is used, the vibration suppressing device can be configured easily and inexpensively without preparing a special mechanism.

  Further, in the vibration suppressing device, in addition to the rotational mass inertial force IF of the rotational mass 18, the viscous body damping force DF of the viscous body 20 is obtained. Further, during the vibration of the bridge 5, the rotation mass 18 rotated by transmission of the displacement of the bridge 5 is not rotated by inertia, but the rotation is attenuated by the viscous body 20. The rotational mass inertia force IF can be appropriately obtained according to the displacement. As described above, vibration of the bridge 5 can be further appropriately suppressed.

  In addition, a mass damper 11 is provided at a central portion of the bridge 5 between two adjacent piers 6, that is, at a portion (antinode) where the displacement of the bridge 5 due to the vibration of the primary mode is maximum, and the cable 31 and 31 are fixed to a portion of the bridge 5 supported by the piers 6 and 6, that is, a portion (node) in which the displacement of the bridge 5 due to the vibration of the primary mode becomes approximately 0, so the primary of the bridge 5 The mode vibration can be more appropriately suppressed.

  In the first embodiment, the vibration suppressing device is configured to correspond to the vibration of the primary mode of the bridge 5, but may be configured to correspond to the vibration of the secondary or higher vibration mode. In this case, the mass damper 11 is provided in a portion (antinode) of the bridge 5 where the displacement due to the vibration in the vibration mode is maximized, and the cables 31 and 31 have a displacement substantially equal to 0 in the vibration mode. Fixed to the site (node). Or you may comprise a vibration suppression apparatus so that the mass damper 11 and the cables 31 and 31 corresponding to each mode may be provided in order to make it respond | correspond to the vibration of a several different vibration mode. In the first embodiment, the tension spring 24 is provided between the outer cylinder 12 and the spring seat 23 in order to apply pretension to the cables 31, 31. You may provide between the parts 32. Alternatively, the tension spring 24 is omitted, and each cable 31 is provided so as to extend in parallel with the bridge 5, and the cable 31 is attached to the bridge 5 via a tension coil spring and pretension is applied by these tension coil springs. May be.

  Next, a vibration suppressing device according to a second embodiment of the present invention will be described with reference to FIG. As shown in the figure, the vibration suppressing device is applied to a high-rise building 7 such as a building unlike the first embodiment. In FIG. 10, the same components as those in the first embodiment are denoted by the same reference numerals. Hereinafter, a description will be given focusing on differences from the first embodiment. The vibration suppression device shown in FIG. 10 is composed of a pair of vibration suppression devices including a first vibration suppression device 41 and a second vibration suppression device 42. These first and second vibration suppression devices 41, 42 are: The building 7 is provided symmetrically.

  The first vibration suppression device 41 includes a mass damper 51 and a cable 31. Similar to the mass damper 11 of the first embodiment, the mass damper 51 includes an outer cylinder 51a, a ball screw having a screw shaft 51b, a rotary mass, a one-way clutch, and a viscous body. In the mass damper 51, the rotational direction in which the one-way clutch functions is opposite to that of the one-way clutch 19 of the first embodiment, so that the mass damper reaction force RF is obtained only during its expansion, and the value during compression is 0. About the other point, since the structure of the mass damper 51 is the same as the mass damper 11, the detailed description shall be abbreviate | omitted.

  The outer cylinder 51a is integrally provided with a connecting member 21 at an end opposite to the screw shaft 51b. The connecting member 21 is rotatably connected to a mounting flange 22. ing. The mass damper 51 is fixed to the ground via the flange 22 and the fixture 33, and is located at the left end of the building 7. Further, a spring seat 23 is attached to the screw shaft 51b, and a tension spring 25 is provided between the outer cylinder 51a and the spring seat 23. Unlike the first embodiment, the tension spring 25 is not a compression coil spring but a tension coil spring.

  Furthermore, one end of the cable 31 is fixed to the upper end of the left end of the building 7. The other end of the cable 31 is connected to the mass damper 51 by being rotatably attached to the spring seat 23 via the fixture 34. The cable 31 is pulled downward by the urging force of the tension spring 25 acting through the spring seat 23 and the fixture 34. Thereby, pretension is applied to the cable 31 and prestress is applied to the building 7. In this state, the mass damper 51 is in a neutral state.

  In the first vibration suppression device 41 and the building 7 configured as described above, as shown by a two-dot chain line in FIG. 10, when the building 7 swings to the right due to the vibration of the primary mode, the displacement of the building 7 with respect to the ground Is transmitted to the mass damper 51 via the cable 31. As a result, the mass damper 51 is expanded, and as described above, the vibration suppression effect by the mass damper reaction force RF is obtained. In this case, the mass damper reaction force RF acts in a direction that increases the tension of the cable 31. The model of the first vibration suppression device 41 in this case is shown in the same manner as in FIG.

  On the other hand, when the building 7 swings to the left due to the vibration of the primary mode, as shown by a one-dot chain line in FIG. 10, the displacement of the building 7 is transmitted to the mass damper 51 via the cable 31. Due to this and the urging force of the tension spring 25 acting, the mass damper 51 is compressed. In this case, if a mass damper reaction force RF is generated, the mass damper reaction force RF acts in a direction to reduce the tension of the cable 31. On the other hand, in the first vibration suppression device 41, as described above, the mass damper reaction force RF becomes 0 during compression of the mass damper 51, so that the cable 31 does not loosen due to the influence of the mass damper reaction force RF. The tension spring 25 holds the tension state. The model of the first vibration suppression device 41 in this case is shown in the same manner as in FIG.

  Further, the second vibration suppression device 42 includes a mass damper 51 and a cable 31, similarly to the first vibration suppression device 41. The mass damper 51 is fixed to the ground via the flange 22 and the fixture 33 and is located at the right end of the building 7. Moreover, the one end part of the cable 31 is being fixed to the upper end part of the right end part of the building 7, and the other end part of the cable 31 is rotatably attached to the spring seat 23 via the fixture 34. The mass damper 51 is connected. The cable 31 is pulled downward by the urging force of the tension spring 25 acting via the spring seat 23 and the fixture 34. Thereby, pretension is applied to the cable 31 and prestress is applied to the building 7. In this state, the mass damper 51 is in a neutral state.

  In the second vibration suppressing device 42 and the building 7 having the above-described configuration, as shown by a one-dot chain line in FIG. 10, when the building 7 swings to the left due to the primary mode vibration, the mass damper 51 is thereby extended. As a result, similarly to the first vibration suppression device 41, the vibration suppression effect by the mass damper reaction force RF is obtained. In this case, the mass damper reaction force RF acts in a direction that increases the tension of the cable 31. The model of the second vibration suppressing device 42 in this case is shown in the same manner as in FIG.

  On the other hand, as shown by a two-dot chain line in FIG. 10, when the building 7 is swung to the right by the vibration of the primary mode, the mass damper 51 is caused by the fact that the urging force of the tension spring 25 acts. Compressed. In this case, if a mass damper reaction force RF is generated, the mass damper reaction force RF acts in a direction to reduce the tension of the cable 31. On the other hand, in the second vibration suppression device 42, the mass damper reaction force RF becomes 0 during compression of the mass damper 51, as in the first vibration suppression device 41, so that the cable 31 loosens due to the influence of the mass damper reaction force RF. Without being held in tension by the tension spring 25. The model of the second vibration suppressing device 42 in this case is shown in the same manner as in FIG.

  Further, the mass of the rotating mass of the first and second vibration suppressing devices 41 and 42, the viscosity coefficient of the viscous body, the spring constant of the tension spring 25, and the rigidity of the cable 31 are the same as the rotational mass, the viscous body, the tension spring 25 and the cable. The natural frequency of the additional vibration system 31 is set to a value that is synchronized with the natural frequency of the primary mode of the building 7.

  As described above, according to the second embodiment, as in the first embodiment, even when the pretension applied to the cable 31 is relatively small, the cable 31 can always be held in tension during vibration of the building 7. Therefore, the displacement of the building 7 can be appropriately transmitted to the ball screw of the mass damper 51 via the cable 31 and appropriately converted into the rotational motion of the rotary mass. Therefore, the vibration suppressing effect by the vibration suppressing device can be appropriately obtained, and in addition, the vibration of the building 7 can be appropriately suppressed by synchronizing the natural frequency of the additional vibration system with respect to the building 7. Can do. In addition, the mass damper 51 is fixed to the ground supporting the building 7, and one end of the cable 31 is at the upper end of the building 7, that is, the displacement of the building 7 due to the vibration in the primary mode is maximized. Since it is being fixed to the site | part (abdomen), the vibration of the primary mode of the building 7 can be suppressed more appropriately. In addition, about the building 7, the effect mentioned above by 1st Embodiment can be acquired similarly.

  In the second embodiment, the mass damper 51 is fixed to the ground and the cable 31 is fixed to the building. Conversely, the cable 31 is fixed to the ground and the mass damper 51 is fixed to the building 7. It may be fixed to. In this case, the cable 31 is connected to the building 7 via the mass damper 51. Moreover, in 2nd Embodiment, although the mass damper 51 is being fixed to the ground, in the building 7 in the site | part (node) where the displacement by the vibration of a primary mode becomes a value of 0, ie, the lower end part of the building 7 It may be fixed to. Alternatively, the cable 31 is composed of a pair of cables, and one end portions of the pair of cables are connected to each other via the mass damper 51, and one other end portion of the pair of cables is fixed to the upper end portion of the building 7. The other end of the other pair of cables may be fixed to the ground or the lower end of the building 7.

  Furthermore, in 2nd Embodiment, although the vibration suppression apparatus is comprised so that it may respond to the vibration of the primary mode of the building 7, you may comprise so that it may respond to the vibration of a secondary mode. FIG. 11 shows a vibration suppressing device according to the third embodiment of the present invention configured as described above. In the figure, the same components as those in the first and second embodiments are denoted by the same reference numerals. Hereinafter, a description will be given focusing on differences from the first and second embodiments.

  As shown in FIG. 11, the vibration suppression device is composed of a pair of vibration suppression devices including a first vibration suppression device 61 and a second vibration suppression device 62, and these first and second vibration suppression devices 61, 62 is provided in the building 7 symmetrically. The 1st vibration suppression apparatus 61 is provided with the mass damper 11 and the cables 31 and 31 similarly to 1st Embodiment. These cables 31 and 31 are connected to each other by connecting one end portions thereof to the connecting portion 32, and are provided symmetrically about the connecting portion 32 in the vertical direction of the building 7. Moreover, the other end part of one cable 31 is being fixed to the left end part of the upper end part of the building 7, and the other end part of the other cable 31 is being fixed to the ground, The left end part of the building 7 Is located.

  Further, the mass damper 11 is fixed to the building 7 by attaching the flange 22 to the left end portion of the building 7 via the fixture 33, and the spring seat 23 is rotatably attached to the connecting portion 32. Thus, the cables 31 and 31 are connected. In this state, the mass damper 11 is in a neutral state, and is located at a central portion in the vertical direction of the building 7. The cables 31 and 31 are urged to the right by the urging force of the tension spring 24, whereby pretension is applied to the cables 31 and 31 and prestress is applied to the building 7. ing.

  In the first vibration suppressing device 61 and the building 7 having the above-described configuration, as shown by a two-dot chain line in FIG. Then, it is transmitted to the mass damper 11 via the cables 31 and 31. As a result, as a result of the mass damper 11 being compressed, the vibration suppression effect by the mass damper reaction force RF is obtained as in the first embodiment. In this case, the mass damper reaction force RF acts in a direction to increase the tension of the cables 31 and 31. The model of the first vibration suppressing device 61 in this case is shown in the same manner as in FIG.

  On the other hand, when the building 7 is swung to the left by the vibration in the secondary mode, as shown by a one-dot chain line in FIG. 11, the displacement of the building 7 is transmitted to the mass damper 11 via the cables 31 and 31. Due to this and the urging force of the tension spring 24 acting, the mass damper 11 is extended. In this case, if a mass damper reaction force RF is generated, the mass damper reaction force RF acts in a direction to reduce the tension of the cables 31 and 31. On the other hand, in the first vibration suppression device 61, the mass damper reaction force RF becomes 0 while the mass damper 11 is extended, as in the first embodiment. Therefore, the cables 31 and 31 are constructed by the influence of the mass damper reaction force RF. It follows the object 7 and does not move to the left or loosen thereby, and is held in tension by the tension spring 24. The model of the first vibration suppressing device 61 in this case is shown in the same manner as in FIG.

  The second vibration suppression device 62 includes the mass damper 11 and the cables 31 and 31 as in the first vibration suppression device 61. The cables 31, 31 of the second vibration suppression device 62 are provided symmetrically about the connecting portion 32 as in the first vibration suppression device 61, and the other end of the one cable 31 is the upper end of the building 7. The other end of the other cable 31 is fixed to the ground and is located at the right end of the building 7.

  Further, the mass damper 11 is fixed to the building 7 by the flange 22 being attached to the right end portion of the building 7 via the fitting 33, and the spring seat 23 is rotatably attached to the connecting portion 32. Thus, the cables 31 and 31 are connected. In this state, the mass damper 11 is in a neutral state, and is located at a central portion in the vertical direction of the building 7. The cables 31 and 31 are urged to the left by the urging force of the tension spring 24, whereby pretension is applied to the cables 31 and 31 and prestress is applied to the building 7. ing.

  In the second vibration suppression device 62 and the building 7 having the above-described configuration, as shown by a one-dot chain line in FIG. 11, when the building 7 swings to the left due to the vibration of the secondary mode, the mass damper 11 is compressed. As a result, the vibration suppression effect by the mass damper reaction force RF is obtained as in the first embodiment. In this case, the mass damper reaction force RF acts in a direction to increase the tension of the cables 31 and 31. The model of the second vibration suppression device 62 in this case is shown in the same manner as in FIG.

  On the other hand, as shown by a two-dot chain line in FIG. 11, when the building 7 is swung to the right by the vibration of the secondary mode, this and the urging force of the tension spring 24 are acting. Is stretched. In this case, if a mass damper reaction force RF is generated, the mass damper reaction force RF acts in a direction to reduce the tension of the cables 31 and 31. On the other hand, in the second vibration suppression device 62, the mass damper reaction force RF becomes 0 while the mass damper 11 is extended, as in the first embodiment. Therefore, the cables 31 and 31 are constructed by the influence of the mass damper reaction force RF. It follows the object 7 and does not move to the right or loosen by it, and is held in tension by the tension spring 24. The model of the second vibration suppression device 62 in this case is shown in the same manner as in FIG.

  Further, the mass of the rotary mass 18 of the first and second vibration suppressing devices 61 and 62, the viscosity coefficient of the viscous body 20, the spring constant of the tension spring 24, and the rigidity of the cables 31 and 31 are the same as those of the rotary mass 18 and the viscous body 20. The natural frequency of the additional vibration system including the tension spring 24 and the cables 31 and 31 is set to a value that synchronizes with the natural frequency of the secondary mode of the building 7.

  As described above, according to the third embodiment, as in the first embodiment, even when the pretension applied to the cables 31 and 31 is relatively small, the cables 31 and 31 are always tensioned during vibration of the building 7. Since the state can be maintained, the displacement of the building 7 can be appropriately transmitted to the ball screw 13 via the cables 31 and 31 and can be appropriately converted into the rotational motion of the rotary mass 18. Therefore, the vibration suppressing effect by the vibration suppressing device can be appropriately obtained, and in addition, the vibration of the building 7 can be appropriately suppressed by synchronizing the natural frequency of the additional vibration system with respect to the building 7. Can do. Moreover, the 1st and 2nd vibration suppression apparatuses 61 and 62 are provided in the site | part of the center of the up-down direction in the building 7, ie, the site | part (belly) where the displacement of the building 7 by the vibration of a secondary mode becomes the maximum. The cables 31 and 31 are connected to the upper end of the building 7, that is, the portion (node) where the displacement of the building 7 due to the vibration of the secondary mode is almost 0 and the ground supporting the building 7. Since it is being fixed, the vibration of the secondary mode of the building 7 can be suppressed further appropriately. In addition, about the building 7, the effect mentioned above by 1st Embodiment can be acquired similarly.

  In addition, in 3rd Embodiment, although the vibration suppression apparatus is comprised so that it may respond to the vibration of the secondary mode of the building 7, you may comprise so that it may respond to the vibration of the vibration mode more than tertiary. . In this case, the mass damper 11 is provided in a part (abdomen) of the building 7 where the displacement due to the vibration in the vibration mode is maximized, and the cables 31 and 31 have a displacement of approximately 0 as the displacement due to the vibration in the vibration mode. It is fixed to the part (node). Alternatively, the vibration suppression device may be configured to include the mass damper 11 and the cables 31 and 31 corresponding to each mode in order to correspond to a plurality of different vibration modes. In the third embodiment, the tension spring 24 is provided between the outer cylinder 12 and the spring seat 23 in order to apply pretension to the cables 31 and 31, but the building 7 and the spring seat 23 or You may provide between the connection parts 32. FIG. Alternatively, the tension spring 24 is omitted, the cables 31 are provided so as to extend in parallel with the building 7, and the cables 31 and 31 are respectively attached to the building 7 and the ground via tension coil springs, Pretension may be applied by a coil spring.

  In addition, this invention can be implemented in various aspects, without being limited to the described embodiment. For example, in the first to third embodiments (hereinafter collectively referred to as “embodiments”), the cables 31 and 31 are steel wires, as long as they exhibit rigidity by applying tension. For example, a strip-shaped steel plate may be used. In the embodiment, the conversion mechanism in the present invention is the ball screw 13, but any other suitable mechanism may be used as long as it can convert the displacement of the structure transmitted via the cable into a rotational motion. For example, a rack and pinion mechanism having a rack and a pinion that mesh with each other may be used.

  Further, in the embodiment, the transmission mechanism in the present invention is the ratchet type one-way clutch 19, but any other suitable mechanism may be used as long as the mechanism can achieve the function of the transmission mechanism described in the claims. For example, a sprag type or roller type one-way clutch may be used. Alternatively, as a transmission mechanism, a clutch capable of controlling the engagement / release of the clutch may be used, and the function of the transmission mechanism may be achieved by controlling the clutch. In the embodiment, the spline groove 14b is formed on the screw shaft 14 and the hemispherical groove 17c is formed on the guide 17. On the contrary, the hemispherical groove is formed on the screw shaft 14. At the same time, a spline groove may be formed in the guide 17.

  Furthermore, in the embodiment, the viscous body 20 is used as the damping element of the present invention. However, other elements such as viscoelastic rubber, pneumatic or magnetic type can be used as long as the rotation of the rotary mass 18 can be attenuated. A damper may be used. In the embodiment, the screw shaft 14 is fixed to the cable 31, and the outer cylinder 12 is fixed to the bridge 5, the ground or the building 7. Conversely, the screw shaft 14 is fixed to the bridge 5, the ground or You may fix the outer cylinder 12 to the cable 31 in the building 7, respectively. In this case, since the reaction torque does not act on the outer cylinder 12 fixed to the cable 31, the guide 17 can be omitted.

  Furthermore, in the embodiment, the vibration suppressing device is constituted by a pair of first and second vibration suppressing devices 1, 2, 41, 42, 61, 62, but both 1, 2, 41, 42, 61, One of 62 may be omitted. In the embodiment, the vibration suppression device is applied to the bridge 5 or the building 7, but may be applied to other structures such as a building beam or a steel tower. In addition, it is possible to appropriately change the detailed configuration within the scope of the gist of the present invention.

1 First vibration suppression device (vibration suppression device)
2 Second vibration suppression device (vibration suppression device)
5 Bridge (structure)
7 Buildings (structures)
13 Ball screw (conversion mechanism)
14 Screw shaft 15 Ball 16 Nut (Rotating body)
17 Guide 18 Rotating mass 19 One-way clutch (transmission mechanism)
20 Viscous material (damping element)
31 Cable 41 First vibration suppression device (vibration suppression device)
42 Second vibration suppression device (vibration suppression device)
61 First vibration suppression device (vibration suppression device)
62 Second vibration suppression device (vibration suppression device)

Claims (5)

A vibration suppressing device for suppressing vibration of a structure,
A tension is applied in advance and the cable is connected to the structure;
A conversion mechanism that has a rotating body, is connected to the cable, is generated by vibration of the structure, and is transmitted through the cable, and converts the displacement of the structure into a rotational motion of the rotating body;
A rotatable mass,
A reaction force from the rotating mass, which is connected to the rotating body and the rotating mass and is generated along with the transmission of the rotating force from the rotating body to the rotating mass during the vibration of the structure, causes the tension of the cable. When acting in the increasing direction, transmission of the rotational force from the rotating body to the rotating mass is allowed, and when the reaction force from the rotating mass acts in the direction of reducing the tension of the cable, the rotating body A transmission mechanism that blocks transmission of rotational force from the rotary mass to the rotary mass;
A vibration suppressing device comprising: The vibration suppression device is
It is composed of a pair of vibration suppression devices each including the cable, the conversion mechanism, the rotating mass, and the transmission mechanism,
During the vibration of the structure, when the reaction force from one rotating mass of the pair of vibration suppressing devices acts in a direction to reduce the tension of the one cable, the other rotating mass of the pair of vibration suppressing devices. When the reaction force from the other rotating mass acts in a direction to increase the tension of the other cable and the reaction force from the other rotating mass acts in a direction to reduce the tension of the other cable, The vibration suppressing device according to claim 1, wherein the reaction force from the rotating mass is configured to act in a direction in which the tension of the one cable is increased. The conversion mechanism has a screw shaft connected to the cable, and the screw shaft reciprocates in the axial direction of the screw shaft as the displacement of the structure is transmitted through the cable. Is configured to
The rotating body is constituted by a nut that is screwed to the screw shaft via a ball and converts a reciprocating movement in the axial direction of the screw shaft into a rotational motion,
The vibration suppressing device according to claim 1, wherein the conversion mechanism further includes a guide that guides the reciprocating movement of the screw shaft in the axial direction so that the screw shaft does not rotate.   The vibration suppressing device according to claim 3, wherein the transmission mechanism is a one-way clutch.   The vibration suppressing device according to claim 1, further comprising a damping element that attenuates rotation of the rotating mass.

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