Mass damper

Abstract

To provide a mass damper that can use a weight having relatively large mass, can set the resonant frequency low, and does not require a device to be vibration-damped to support the mass of the weight.SOLUTION: A mass damper comprises a first beam-shaped member and a second beam-shaped member, each of which has a flat plate portion that stands vertically relative to a damper installation part, and each of which is arranged in an orientation parallel to a first horizontal direction, and a connection mechanism that connects the first beam-shaped member and the second beam-shaped member. The first beam-shaped member has a connection portion that is connected to the tip side of a device to be vibration-damped, and the second beam-shaped member has a base portion for fixing the second beam-shaped member to the damper installation part below the first beam-shaped member. A weight is attached to the flat plate portion of the second beam-shaped member, and the load of the second beam-shaped member including the weight and the base portion is supported by the damper installation part.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a mass damper. [Background technology]

[0002] Mass dampers are sometimes used to reduce the vibration of vibration-damped equipment. A mass damper is a device consisting of a weight, a spring, and a damper, and is also called a dynamic vibration absorber. A mass damper suppresses the vibration of a vibration-damped equipment by matching the natural frequency of the mass damper with the natural frequency of the vibration-damped equipment in which the mass damper is installed. When the vibration-damped equipment is excited near its resonant frequency, the mass damper resonates and the damper in the mass damper dissipates energy, thereby damping the vibration of the equipment. If the mass of the equipment to be damped is large, the energy held by the equipment when excited is large, so the mass of the weight of the mass damper used for vibration damping must also be set to a certain degree. In general, it is desirable for the mass of the weight of the mass damper to be 1% or more of the mass of the equipment to be damped.

[0003] Incidentally, a nuclear power plant is equipped with multiple pieces of large equipment. When earthquake motion is input to a nuclear power plant, it is expected that these pieces of large equipment will vibrate. In particular, since large equipment has a large mass, the natural frequency of the large equipment tends to decrease. Therefore, when earthquake motion in the main frequency band of 5 to 15 Hz is input to a nuclear power plant, it is possible that the natural vibration of the large equipment will be excited. However, even if the large equipment has a large mass, if the equipment is firmly installed on the ground, the spring constant of the support member supporting the large equipment will increase, and the natural frequency may deviate from the main frequency band of the earthquake motion.

[0004] Here, it is considered that the equipment installed around the reactor pressure vessel may have a large mass and, depending on the fixing conditions, the spring constant of the support member may not be large. The reason is that around the reactor pressure vessel, multiple equipment are present in a relatively narrow space, so the handling of the support members is limited. If equipment with a relatively large mass resonates due to earthquake motion in the narrow area around the reactor pressure vessel, the structural integrity of the equipment may be reduced and adverse effects may be caused by contact with surrounding equipment. Also, since the number of support members installed in the narrow area is limited, the few support members may bear a large load and the function of the support members may not be maintained.

[0005] The equipment installed around the reactor pressure vessel described above is set as the vibration-damping target equipment, and a mass damper can be used to reduce the vibration of the vibration-damping target equipment. In this case, the natural frequency of the vibration-damping target equipment is assumed to be about 5 to 15 Hz, which is the main frequency band of earthquake motion. For this reason, the resonant frequency of the mass damper needs to be set low to match the natural frequency of the vibration-damping target equipment. To set the resonant frequency of the mass damper low, it is necessary to reduce the spring constant in the vibration direction of the support structure that supports the mass damper weight, in other words, to reduce the rigidity of the support structure in the vibration direction. As mentioned above, when the mass of the vibration-damping target equipment is large, the mass of the mass damper weight also needs to be set relatively large. For this reason, the mass damper is structured to support a relatively large mass by a support structure that has low rigidity in the vibration direction.

[0006] A mass damper vibrates strongly when the equipment to be damped is excited at the resonant frequency of the mass damper, and absorbs the vibration of the equipment. On the other hand, when the equipment to be damped is excited at a frequency other than the resonant frequency of the mass damper, the vibration damping effect of the mass damper may not be very high. For this reason, it is necessary to determine the application of a mass damper after taking into consideration the natural frequency of the equipment to be damped, the amplitude at which the equipment vibrates, and the main frequency band of vibration applied to the equipment to be damped.

[0007] Patent Document 1 describes a technique related to a mass damper (leaf spring type dynamic vibration absorber) in which the base end of a support arm is fixed to a target device (object to be vibration-damped) by a fixing means and a weight is provided at the tip of the support arm. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] JP 2005-351366 A Summary of the Invention [Problem to be solved by the invention]

[0009] If the mass of the equipment to be damped is large and the rigidity of the support member that supports the equipment is low, the resonant frequency of the equipment to be damped will be low. In this case, the resonant frequency of the corresponding mass damper must be set low. Also, to ensure the damping effect of the mass damper, the mass of the mass damper must be large for equipment to be damped that has a large mass. However, the damping effect of the mass damper is only exerted when earthquake motion occurs, and it is desirable to reduce the increase in load caused by the mass damper during normal times other than those.

[0010] However, in the technology described in Patent Document 1, the mass damper is fixed to the target equipment by the fixing means, so the mass of the mass damper, including the weight and support arm, is added directly to the mass of the target equipment. As a result, the target equipment supports the mass of the mass damper, making it impossible to reduce the increase in load caused by the mass damper.

[0011] The present invention proposes a mass damper that can use a weight with a relatively large mass, can set the resonant frequency low, and does not require the weight to be supported by the equipment to be vibration-damped, with the aim of being installed in equipment with a large mass. [Means for solving the problem]

[0012] In order to solve the above problems, for example, the configurations described in the claims are adopted. The present application includes a number of means for solving the above problems, and one of them is a mass damper for use in a vibration-damping target device that is supported by an equipment support member and extends from the equipment support member in a first horizontal direction. The mass damper includes a first beam member and a second beam member, each of which has a flat plate portion, the flat plate portion standing vertically relative to a damper installation portion, and which is arranged in a direction parallel to the first horizontal direction, and a connecting mechanism that connects the first beam member and the second beam member. The first beam member has a connection portion that is connected to the tip side of the vibration-damping target device. The second beam member has a base portion for fixing the second beam member to the damper installation portion below the first beam member. A weight is attached to the flat plate portion of the second beam member. The load of the second beam member including the weight and the base portion is supported by the damper installation portion. Effect of the Invention

[0013] According to the present invention, it is possible to provide a mass damper which allows the use of a weight with a relatively large mass, allows the resonant frequency to be set low, and does not require the device to be vibration-damped to support the mass of the weight. Problems, configurations and effects other than those described above will become apparent from the following description of the embodiments. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a schematic perspective view showing an installation state of a vibration-damping target device in an embodiment of the present invention. [Diagram 2] 1 is a schematic perspective view showing a configuration of a mass damper according to a first embodiment of the present invention. FIG. [Diagram 3] 3 is a cross-sectional view of the mass damper shown in FIG. 2 taken along line AA. [Figure 4] FIG. 11 is a schematic perspective view showing the configuration of a mass damper according to a second embodiment of the present invention. [Diagram 5] 5 is a cross-sectional view of the mass damper shown in FIG. 4 taken along line BB. [Figure 6]FIG. 11 is a perspective view of a first beam member included in a mass damper according to a second embodiment of the present invention. [Figure 7] FIG. 11 is a perspective view of a connecting member provided in a mass damper according to a second embodiment of the present invention. [Figure 8] FIG. 11 is an exploded perspective view showing the configuration of a mass damper according to a third embodiment of the present invention. [Figure 9] 9 is a cross-sectional view taken along line CC in the assembled state of the mass damper shown in FIG. 8. [Figure 10] FIG. 11 is a rear view of a rotating member included in a mass damper according to a third embodiment of the present invention. [Figure 11] FIG. 11 is an exploded perspective view showing the configuration of a mass damper according to a fourth embodiment of the present invention. [Figure 12] 12 is a cross-sectional view taken along line DD in the assembled state of the mass damper shown in FIG. 11. [Figure 13] 12 is a cross-sectional view taken along line EE in the assembled state of the mass damper shown in FIG. 11. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In this specification and the drawings, elements having substantially the same functions or configurations are given the same reference numerals, and duplicated descriptions are omitted as appropriate. In addition, the following description and drawings are examples for explaining the present invention, and may be omitted or simplified for convenience of explanation. Each component may be singular or plural, unless otherwise limited. In addition, the position, size, shape, range, etc. of each component shown in the drawings may not represent the actual position, size, shape, range, etc., in order to facilitate understanding of the invention.

[0016] FIG. 1 is a schematic perspective view showing an installation state of a device to be subjected to vibration damping in an embodiment of the present invention. In this specification, in order to clarify the shape and positional relationship of each part, the first horizontal direction is defined as the X direction, the second horizontal direction is defined as the Y direction, and the vertical direction is defined as the Z direction. The X direction, Y direction, and Z direction are perpendicular to each other.

[0017] As shown in Fig. 1, the vibration-damping target equipment 1 is supported by an equipment support member 2. A base end portion 1a of the vibration-damping target equipment 1 is fixed to the equipment support member 2 by, for example, welding, bolts, or the like. The vibration-damping target equipment 1 is disposed extending in the X-direction from the equipment support member 2. Therefore, a tip end portion 1b of the vibration-damping target equipment 1 is located on the opposite side to the base end portion 1a of the vibration-damping target equipment 1 in the longitudinal direction of the vibration-damping target equipment 1.

[0018] The equipment support member 2 is loaded with a load due to the mass of the vibration-damping target equipment 1, and this load is supported by the equipment support member 2. When earthquake motion is input to the equipment support member 2 while the vibration-damping target equipment 1 is supported by the equipment support member 2 in this manner, and the vibration-damping target equipment 1 vibrates as a result, the direction in which the vibration-damping target equipment 1 vibrates significantly is the Y direction. There are two main reasons for this. The first reason is that earthquake motion causes larger vibrations in the horizontal direction than in the vertical direction (Z direction). The second reason is that the vibration-damping target equipment 1 extends from the equipment support member 2 in the first horizontal direction (X direction), and the vibration-damping target equipment 1 is less likely to vibrate in the first horizontal direction. For this reason, in order to suppress the vibration of the vibration-damping target equipment 1 caused by earthquake motion, it is effective to suppress the vibration of the vibration-damping target equipment 1 in the second horizontal direction (Y direction). Below, the configuration of a mass damper used to suppress the vibration of the vibration-damping target equipment 1 will be described.

[0019] First Embodiment Fig. 2 is a schematic perspective view showing the configuration of the mass damper according to the first embodiment of the present invention, Fig. 3 is a cross-sectional view of the mass damper shown in Fig. 2 taken along line AA. 2 and 3, the mass damper 10 includes a first beam member 11, a second beam member 12, and a connecting mechanism 13. The mass damper 10 is installed on a damper installation section 14. The damper installation section 14 is disposed below the vibration damping target equipment 1 at a predetermined distance. The damper installation section 14 is made of, for example, a steel frame material.

[0020] (First beam member 11) The first beam member 11 has two plate-shaped parts 15, 16 as flat plate parts, and a pair of connecting parts 17 connecting these two plate-shaped parts 15, 16. Each of the plate-shaped parts 15, 16 is arranged in a state of standing vertically with respect to the damper installation part 14. In addition, each of the plate-shaped parts 15, 16 is arranged in a direction parallel to the X direction. Therefore, the surface direction of each of the plate-shaped parts 15, 16 is parallel to the XZ plane, and the thickness direction of each of the plate-shaped parts 15, 16 is parallel to the Y direction. When the mass damper 10 is viewed from the front direction (Y direction), the plate-shaped part 15 is formed in a rectangular shape, and the plate-shaped part 16 is also formed in a rectangular shape. Each of the plate-shaped parts 15, 16 is preferably made of a vibration-damping steel plate. The vibration-damping steel plate has a structure in which a viscoelastic resin is sandwiched between two steel plates.

[0021] In the Z direction, the plate-shaped portion 15 is disposed above the plate-shaped portion 16. The plate-shaped portion 15 has the same width as the plate-shaped portion 16 and is disposed directly above the plate-shaped portion 16. The upper end of the connecting portion 17 is fixed to the lower end of the plate-shaped portion 15, and the lower end of the connecting portion 17 is fixed to the upper end of the plate-shaped portion 16. In the X direction, a space 18 is formed between the pair of connecting portions 17. The first beam member 11 is connected to the tip side of the vibration-damping target device 1. Specifically, the upper end side of the plate-shaped portion 15 of the first beam member 11 is a connection portion 11a, and this connection portion 11a is fixed to the tip side of the vibration-damping target device 1 by a plurality of bolts 19 (three in the illustrated example). The plurality of bolts 19 are disposed at appropriate intervals in the X direction. The plate-shaped portion 15 is fixed to the side surface 1c of the vibration-damping target device 1 by a plurality of bolts 19.

[0022] (Second beam member 12) The second beam member 12 has a plate-shaped portion 21 as a flat plate portion and a base portion 22 for fixing the second beam member 12 to the damper installation portion 14. When the mass damper 10 is viewed from the front direction, the plate-shaped portion 21 is formed in a substantially rectangular shape. Of the plate-shaped portion 21 and the base portion 22, at least the plate-shaped portion 21 is preferably made of a vibration-damping steel plate. The plate-shaped portion 21 is arranged in a state in which it stands perpendicular to the damper installation portion 14. The plate-shaped portion 21 is arranged in a direction parallel to the X direction. Therefore, the surface direction of the plate-shaped portion 21 is a direction parallel to the XZ plane, and the thickness direction of the plate-shaped portion 21 is a direction parallel to the Y direction. The width of the plate-shaped portion 21 is narrower than the widths of the plate-shaped portions 15 and 16 described above. The widths of the plate-shaped portions 21, 15, and 16 are dimensions defined in the X direction. A space 23 having a rectangular shape in front view is formed on the upper end side of the second beam member 12. As shown in Fig. 3, a gap dimension T1 of the space 23 is set to be slightly larger than a thickness dimension T2 of the plate-shaped portion 16. A height dimension H1 of the space 23 is set to be larger than a height dimension H2 of the plate-shaped portion 16 by a predetermined amount. The space 23 is formed inside the plate-shaped portion 21, penetrating the plate-shaped portion 21 in the X direction.

[0023] The second beam member 12 is, for example, an inverted T-shaped member obtained by integrating two L-shaped members by bolts, welding, or the like. In this case, a recess is formed in each L-shaped member to form the above-mentioned space portion 23. A weight 25 is attached to the plate-shaped portion 21. A weight used in a mass damper is also called an added mass. The weight 25 is attached at a position separated by an appropriate distance from the base portion 22. The appropriate distance described here refers to a distance within a range in which the beam structure portion 24 (see FIG. 2) can be vibrated by utilizing the mass of the weight 25. This point is similar to other embodiments described later. The beam structure portion 24 is a structure obtained by connecting the first beam member 11 and the second beam member 12 by a connecting mechanism 13.

[0024] As shown in FIG. 3, the weight 25 is attached to both sides of the plate-shaped portion 21 by bolts 26 and nuts 27 at a position lower than the space portion 23. In this case, the weight 25 and the plate-shaped portion 21 are provided with through holes for passing the male threads of the bolts 26. In this embodiment, as an example, the weight 25 is attached to the plate-shaped portion 21 by the bolts 26 and nuts 27 at a total of six locations. When the vibration-damping target device 1 vibrates in the Y direction due to seismic motion, the weight 25 vibrates the beam structure portion 24 so as to cancel the vibration of the vibration-damping target device 1. The base portion 22 is disposed at the lower end of the second beam-shaped member 12. The base portion 22 is a portion for fixing the second beam-shaped member 12 to the damper installation portion 14 below the first beam-shaped member 11. The base portion 22 is fixed to the damper installation portion 14 by, for example, bolts or the like, with the base portion 22 placed on the damper installation portion 14.

[0025] (Connection mechanism 13) The connecting mechanism 13 connects the first beam member 11 and the second beam member 12 in a state where the first beam member 11 and the second beam member 12 are not constrained in the in-plane direction but are constrained in the out-of-plane direction. Specifically, the connecting mechanism 13 connects the first beam member 11 and the second beam member 12 in a state where the plate-shaped portion 16 of the first beam member 11 is inserted into the space portion 23 of the second beam member 12. The in-plane direction is a direction parallel to the X direction and the Z direction. The out-of-plane direction is a direction parallel to the Y direction.

[0026] The plate-like portion 16 is disposed at approximately the center of the space 23 in the Z direction. Therefore, above the space 23, there is a space S1 that allows the plate-like portion 16 to move upward, and below the space 23, there is a space S2 that allows the plate-like portion 16 to move downward. The load due to the mass of the vibration-damping target device 1 is supported by the device support member 2 (see FIG. 1) together with the load due to the mass of the first beam member 11. Therefore, the plate-like portion 16 is inserted into the space 23 of the second beam member 12 so as to be movable in the in-plane direction. Moreover, the movement of the plate-like portion 16 in the out-of-plane direction (Y direction) is restricted by the second beam member 12.

[0027] Here, when the mass of the vibration-damping target device 1 is large, it is necessary to set the mass of the weight 25 to be large accordingly. In this embodiment, the weight 25 is attached to the plate-shaped part 21 by the bolt 26 and the nut 27. In other words, the weight 25 is detachable from the plate-shaped part 21. Therefore, by replacing the weight 25 attached to the plate-shaped part 21 with another weight 25 having a different mass, the mass of the weight 25 in the mass damper 10 can be changed (adjusted). Therefore, when the mass of the vibration-damping target device 1 is large, a weight 25 having a large mass may be attached to the plate-shaped part 21 accordingly. In order to effectively suppress the vibration in the Y direction of the vibration-damping target device 1 caused by seismic motion by the mass damper 10, it is preferable that the effective mass of the weight 25 at the resonance frequency in the Y direction is 1 / 20 or more of the effective mass at the resonance frequency in the Y direction of the vibration-damping target device 1. This point is the same for other embodiments described later.

[0028] In this embodiment, the natural frequency of the vibration damping target device 1 is assumed to be about 5 to 15 Hz. Therefore, the resonant frequency of the mass damper 10 needs to be set low in accordance with the natural frequency of the vibration damping target device 1. In order to set the resonant frequency of the mass damper 10 low, the rigidity in the Y direction of the second beam member 12, which is a support structure supporting the weight 25 of the mass damper 10, needs to be set low. The rigidity in the Y direction of the second beam member 12 is mainly determined by the rigidity of the plate-like portion 21 of the second beam member 12. The plate-like portion 21 is a flat portion with the Y direction as its thickness direction, and therefore has low rigidity in the Y direction. In addition, the plate-like portions 15 and 16 of the first beam member 11 are also flat portions with the Y direction as their thickness direction, and therefore have low rigidity in the Y direction. Therefore, the Y-direction rigidity of the beam structure 24 formed by connecting the first beam member 11 and the second beam member 12 by the connecting mechanism 13 is set low, thereby making it possible to set the resonant frequency of the mass damper 10 low to match the natural frequency of the equipment 1 to be vibration-damped.

[0029] In addition, a pedestal portion 22 is provided at the lower end of the second beam member 12, and this pedestal portion 22 is fixed to the damper installation portion 14. As a result, the load of the second beam member 12 including the weight 25 and the pedestal portion 22 is supported by the damper installation portion 14. For this reason, when the mass damper 10 is installed in the vibration damping target equipment 1, the increase in mass of the vibration damping target equipment 1 is only the mass of the first beam member 11.

[0030] The mass damper 10 according to the first embodiment of the present invention can match the natural frequency of the mass damper 10 to the natural frequency of the vibration-damping target equipment 1 by setting the Y-directional rigidity of the beam structure 24 to be low and using a weight 25 with a large mass. As a result, when the vibration-damping target equipment 1 vibrates in the Y-directional direction due to seismic motion, the mass damper 10 vibrates (resonates) so as to cancel out the vibration. Therefore, the vibration energy of the vibration-damping target equipment 1 can be absorbed by the mass damper 10, and the vibration of the vibration-damping target equipment 1 can be reduced.

[0031] In the mass damper 10 according to the first embodiment of the present invention, when the mass damper 10 is installed in the vibration-damping target device 1 having a large mass, a weight 25 having a relatively large mass can be used in accordance with the mass of the vibration-damping target device 1. The weight 25 is attached to the plate-like portion 21 of the second beam member 12, and the base portion 22 of the second beam member 12 is fixed to the damper installation portion 14. The mass of the weight 25 is supported by the damper installation portion 14 via the second beam member 12. Therefore, the vibration-damping target device 1 does not need to support the mass of the weight 25. The beam structure portion 24 of the mass damper 10 is configured by connecting the first beam member 11 having the plate-like portions 15 and 16 as flat plate portions and the second beam member 12 having the plate-like portion 21 as flat plate portion by the connecting mechanism 13. Therefore, the resonance frequency of the mass damper 10 can be set low.

[0032] Furthermore, when the vibration-damping target equipment 1 is equipment installed in, for example, a nuclear power plant and this vibration-damping target equipment 1 moves in an in-plane direction when the nuclear power plant is started up or shut down, the first beam-like member 11 connected to the vibration-damping target equipment 1 moves in the in-plane direction by the same amount as the vibration-damping target equipment 1. Such movement of the vibration-damping target equipment 1 occurs due to thermal expansion or thermal contraction of the equipment support member 2, etc., when the nuclear power plant is started up or shut down, for example.

[0033] In the mass damper 10 according to the first embodiment of the present invention, the connecting mechanism 13 does not constrain the first beam member 11 and the second beam member 12 in the in-plane direction. Therefore, when the first beam member 11 moves in the in-plane direction by the same amount as the vibration-damping target device 1 as described above, the plate-like portion 16 inserted in the space portion 23 of the second beam member 12 moves, thereby allowing the first beam member 11 to move. Therefore, even if the vibration-damping target device 1 moves in the in-plane direction, no excessive force is applied to the connecting mechanism 13. Therefore, damage to the mass damper 10 can be avoided. Furthermore, even if the first beam member 11 moves in the in-plane direction, the contact area between the plate-like portion 16 and the plate-like portion 21 does not change. Therefore, the constrained state in the out-of-plane direction by the connecting mechanism 13 hardly changes. Therefore, the natural frequency set in the mass damper 10 having the beam structure portion 24 is almost constant regardless of the in-plane movement of the first beam member 11. This makes it easier to match the natural frequency of the mass damper 10 to the natural frequency of the device 1 to be vibration-damped.

[0034] Moreover, in the mass damper 10 according to the first embodiment of the present invention, the plate-like portions 15, 16 of the first beam member 11 and the plate-like portion 21 of the second beam member 12 are both arranged in a state of standing perpendicular to the damper installation portion 14. That is, the mass damper 10 is an upright mass damper. This allows only a small space to be secured for installation of the mass damper 10. Therefore, the mass damper 10 can be installed in a narrow portion where the installation space is restricted, such as a narrow portion around a reactor pressure vessel.

[0035] <Second embodiment> Fig. 4 is a schematic perspective view showing the configuration of a mass damper according to a second embodiment of the present invention, Fig. 5 is a cross-sectional view of the mass damper shown in Fig. 4 taken along line BB. 4 and 5, the mass damper 30 includes a first beam member 31, a second beam member 32, and a connecting mechanism 33. The mass damper 30 is installed on the damper installation portion 14.

[0036] (First beam member 31) The first beam member 31 is formed in a flat plate shape overall. In other words, the first beam member 31 itself constitutes a flat plate portion. The first beam member 31 as a flat plate portion is arranged in a state of standing vertically with respect to the damper installation portion 14. The first beam member 31 is also arranged in a direction parallel to the X direction. Therefore, the surface direction of the first beam member 31 is a direction parallel to the XZ plane, and the thickness direction of the first beam member 31 is a direction parallel to the Y direction. When the mass damper 30 is viewed from the front direction, the first beam member 31 is formed in a vertically long rectangle. The first beam member 31 is preferably made of a vibration-damping steel plate. As shown in FIG. 6, a through hole 34 is provided on the lower end side of the first beam member 31. The through hole 34 is formed in a circular shape.

[0037] The first beam member 31 is connected to the tip side of the vibration-damping target device 1. Specifically, the upper end side of the first beam member 31 forms a connection part 31a, and this connection part 31a is fixed to the tip side of the vibration-damping target device 1 by a plurality of bolts 35 (three in the illustrated example). The plurality of bolts 35 are arranged at appropriate intervals in the X direction. In addition, the first beam member 31 is fixed to the side surface 1c of the vibration-damping target device 1 by the plurality of bolts 35.

[0038] (Second beam member 32) The second beam member 32 has a plate-shaped portion 37 as a flat plate portion and a base portion 38 for fixing the second beam member 32 to the damper installation portion 14. When the mass damper 10 is viewed from the front direction, the plate-shaped portion 37 is formed in a substantially rectangular shape. Of the plate-shaped portion 37 and the base portion 38, at least the plate-shaped portion 37 is preferably made of a vibration-damping steel plate. The plate-shaped portion 37 is disposed in a state in which it stands perpendicular to the damper installation portion 14. The plate-shaped portion 37 is disposed in a direction parallel to the X direction. Therefore, the surface direction of the plate-shaped portion 37 is parallel to the XZ plane, and the thickness direction of the plate-shaped portion 37 is parallel to the Y direction. A space portion 39 that is circular in front view is formed on the upper end side of the second beam member 12. The space portion 39 is formed inside the plate-shaped portion 37. In addition, a circular hole 40 (see FIG. 5) is formed in the second beam member 12. The circular hole 40 is a hole formed in a circular shape when viewed from the Y direction. The circular hole 40 is formed on the back side of the second beam-shaped member 12. The circular hole 40 is also formed in a state of communication with the space portion 39. Communication means spatially connected. The space portion 39 and the circular hole 40 are formed concentrically. The inner diameter of the space portion 39 is larger than the inner diameter of the circular hole 40.

[0039] The second beam member 32 is, for example, an inverted T-shaped member obtained by integrating two L-shaped members with bolts, welding, or the like. In this case, each L-shaped member is formed with a recess for forming the above-mentioned space portion 39. In addition, a weight 41 is attached to the plate-shaped portion 37. The weight 41 is attached at a position spaced an appropriate distance from the base portion 38.

[0040] As shown in FIG. 5, the weight 41 is attached to both sides of the plate-shaped part 37 by bolts 42 and nuts 43 at a position lower than the space part 39. In this case, the weight 41 and the plate-shaped part 37 are provided with through holes for passing the male thread part of the bolt 42. In this embodiment, as an example, the weight 41 is attached to the plate-shaped part 37 by bolts 42 and nuts 43 at a total of six places. When the vibration-damping target equipment 1 vibrates in the Y direction due to seismic motion, the weight 41 vibrates the beam structure part 44 (see FIG. 4) so ​​as to cancel the vibration of the vibration-damping target equipment 1. The beam structure part 44 is a structure obtained by connecting the first beam-shaped member 31 and the second beam-shaped member 32 by the connecting mechanism 33. The pedestal part 38 is disposed at the lower end part of the second beam-shaped member 32. The pedestal part 38 is a part for fixing the second beam-shaped member 32 to the damper installation part 14 below the first beam-shaped member 31. The base portion 38 is fixed to the damper installation portion 14 by, for example, bolts or the like, with the base portion 38 placed on the damper installation portion 14 .

[0041] (Connection mechanism 33) The connecting mechanism 33 connects the first beam member 31 and the second beam member 32 in a state where they are not constrained in the in-plane direction but are constrained in the out-of-plane direction. Specifically, the connecting mechanism 33 has a connecting member 45 for connecting the first beam member 31 and the second beam member 32. As shown in FIG. 7, the connecting member 45 includes a disk portion 46, a shaft portion 47, and a fixing portion 48. As shown in FIG. 5, the disk portion 46 is inserted into the space portion 39 of the plate-shaped portion 37. In order to insert the disk portion 46 into the space portion 39 of the plate-shaped portion 37, it is necessary to place the disk portion 46 of the connecting member 45 in advance in the recess that forms the space portion 39 when the second beam member 32 is formed by integrating two L-shaped members as described above.

[0042] As shown in Fig. 5, the outer diameter D1 of the disc portion 46 is smaller than the inner diameter D2 of the space portion 39. The thickness dimension T3 of the disc portion 46 is set to be slightly smaller than the gap dimension T4 of the space portion 39 so that the disc portion 46 can move in the in-plane direction within the space portion 39. The disc portion 46 is disposed in approximately the center of the space portion 39 when viewed from the Y direction. Therefore, a space S3 that allows the disc portion 46 to move in the in-plane direction exists around the disc portion 46. In addition, the movement of the disc portion 46 in the out-of-plane direction (Y direction) is restricted by the second beam member 32.

[0043] One end of the shaft portion 47 is connected to the center of the disc portion 46. The disc portion 46 and the shaft portion 47 are preferably of an integral structure. However, one end of the shaft portion 47 may be joined to the center of the disc portion 46 by welding or the like. As shown in FIG. 5, the shaft portion 47 passes through the circular hole 40 and the through hole 34. The inner diameter of the through hole 34 is smaller than the inner diameter of the circular hole 40. The inner diameter of the through hole 34 is larger than the outer diameter of the shaft portion 47. A female screw portion is formed on the other end side of the shaft portion 47 by thread cutting.

[0044] The fixing part 48 has a so-called double nut structure in which two nuts are combined (see FIG. 5). The two nuts constituting the fixing part 48 are engaged with a female screw portion formed on the other end side of the shaft part 47. The fixing part 48 fixes the connecting member 45 to the first beam member 31 by a locking force obtained by the double nut structure. This allows the connecting member 45 to move in the in-plane direction integrally with the first beam member 31. However, the tightening torque of the two nuts is adjusted so that the above-mentioned locking force is not strongly applied to the contact interface between the first beam member 31 and the second beam member 32 (plate-shaped part 37). In other words, a weak force is applied to the contact interface between the first beam member 31 and the second beam member 32 such that the first beam member 31 and the second beam member 32 can move relatively in the in-plane direction.

[0045] By configuring the connecting mechanism 33 in this manner, the first beam member 31 and the second beam member 32 can be connected in a state where they are not constrained in the in-plane direction but are constrained in the out-of-plane direction.

[0046] The mass damper 30 according to the second embodiment of the present invention can match the natural frequency of the vibration-damping target equipment 1 with the natural frequency of the vibration-damping target equipment 1 by setting the Y-directional rigidity of the beam structure 44 to be low and using a weight 41 with a large mass. As a result, when the vibration-damping target equipment 1 vibrates in the Y-directional direction due to seismic motion, the mass damper 30 vibrates (resonates) so as to cancel out the vibration. Therefore, the vibration energy of the vibration-damping target equipment 1 can be absorbed by the mass damper 30, and the vibration of the vibration-damping target equipment 1 can be reduced.

[0047] In the mass damper 30 according to the second embodiment of the present invention, when the mass damper 30 is installed in the vibration-damping target device 1 having a large mass, a weight 41 having a relatively large mass can be used in accordance with the mass of the vibration-damping target device 1. The weight 41 is attached to the plate-like portion 37 of the second beam member 32, and the base portion 38 of the second beam member 32 is fixed to the damper installation portion 14. Therefore, the mass of the weight 41 is supported by the damper installation portion 14 via the second beam member 12. Therefore, the vibration-damping target device 1 does not need to support the mass of the weight 41. The beam structure portion 44 of the mass damper 30 is configured by connecting the first beam member 31 as a flat plate portion and the second beam member 32 having the plate-like portion 37 as a flat plate portion by the connecting mechanism 33. Therefore, the resonant frequency of the mass damper 30 can be set low.

[0048] Moreover, in the mass damper 30 according to the second embodiment of the present invention, the connecting mechanism 33 does not constrain the first beam member 31 and the second beam member 32 in the in-plane direction. Therefore, when the first beam member 31 moves in the in-plane direction by the same amount as the vibration-damping target equipment 1 due to thermal expansion or thermal contraction of the equipment support member 2 (see FIG. 1), the movement of the disk portion 46 inserted in the space portion 39 of the second beam member 32 causes the first beam member 31 to be allowed to move. Therefore, even if the first beam member 31 moves in the in-plane direction, no excessive force is applied to the connecting mechanism 33. Therefore, damage to the mass damper 30 can be avoided.

[0049] In the mass damper 30 according to the second embodiment of the present invention, the first beam member 31 serving as a flat plate portion and the plate portion 37 of the second beam member 32 are both arranged standing perpendicular to the damper installation portion 14. In other words, the mass damper 30 is an upright mass damper. This allows the mass damper 10 to be installed in a narrow area with limited installation space.

[0050] <Third embodiment> Fig. 8 is an exploded perspective view showing the configuration of a mass damper according to a third embodiment of the present invention, Fig. 9 is a cross-sectional view taken along line CC in the assembled state of the mass damper shown in Fig. 8. 8 and 9, the mass damper 50 includes a first beam member 51, a second beam member 52, and a connecting mechanism 53. The mass damper 50 is installed on the damper installation portion 14.

[0051] (First beam member 51) The first beam member 51 is formed in a flat plate shape overall. In other words, the first beam member 51 itself constitutes a flat plate portion. The first beam member 51 as a flat plate portion is arranged in a state of standing vertically with respect to the damper installation portion 14. The first beam member 51 is arranged in a direction parallel to the X direction. Therefore, the surface direction of the first beam member 51 is a direction parallel to the XZ plane, and the thickness direction of the first beam member 51 is a direction parallel to the Y direction. When the mass damper 50 is viewed from the front direction, the first beam member 51 is formed in a vertically elongated shape with both ends in the longitudinal direction being rounded. The first beam member 51 is preferably made of a vibration-damping steel plate.

[0052] The first beam member 51 is connected to the tip side of the vibration-damping target device 1. Specifically, the upper end side of the first beam member 51 forms a connection part 51a, and this connection part 51a is fixed to the tip side of the vibration-damping target device 1 by a plurality of bolts 54 (six in the illustrated example). The plurality of bolts 54 are arranged at appropriate intervals. The first beam member 51 is also fixed to the side surface 1c of the vibration-damping target device 1 by the plurality of bolts 54.

[0053] A protrusion 55 is provided on the lower end side of the first beam member 51. The protrusion 55 can be formed of a bolt, for example, as shown in FIG. 9. In this case, a through hole is provided on the lower end side of the first beam member 51 for inserting a male threaded portion 55b of the bolt as the protrusion 55. A head portion 55a and a male threaded portion 55b of the bolt as the protrusion 55 protrude to the back side of the first beam member 51. In addition, two nuts constituting a double nut structure portion 56 are engaged with the male threaded portion 55b of the bolt as the protrusion 55, and the bolt as the protrusion 55 is fixed to the first beam member 51 by appropriately adjusting the tightening torque of each nut.

[0054] (Second beam member 52) As shown in FIG. 8, the second beam member 52 has a plate-shaped portion 57 as a flat plate portion and a base portion 58 for fixing the second beam member 52 to the damper installation portion 14. When the mass damper 50 is viewed from the front direction, the plate-shaped portion 57 is formed in a substantially rectangular shape. Of the plate-shaped portion 57 and the base portion 58, at least the plate-shaped portion 57 is preferably made of a vibration-damping steel plate. The plate-shaped portion 57 is disposed in a state in which it stands perpendicular to the damper installation portion 14. The plate-shaped portion 57 is disposed in a direction parallel to the X direction. Therefore, the surface direction of the plate-shaped portion 57 is parallel to the XZ plane, and the thickness direction of the plate-shaped portion 57 is parallel to the Y direction. The plate-shaped portion 57 has an arc-shaped groove portion 59 formed therein. The groove portion 59 is provided on the upper end side of the second beam member 52. The groove portion 59 may or may not penetrate the plate-shaped portion 57 in the thickness direction.

[0055] The second beam member 52 is, for example, an inverted T-shaped member obtained by integrating two L-shaped members with bolts, welding, or the like. In this case, of the two L-shaped members, at least the L-shaped member arranged on the side facing the first beam member 51 has the above-mentioned groove portion 59 formed therein. In addition, a weight 61 is attached to the plate-shaped portion 57. The weight 61 is attached at a position spaced an appropriate distance from the base portion 58. The attachment structure of the weight 61 is similar to the attachment structure of the weight 25 in the first embodiment described above and the attachment structure of the weight 41 in the second embodiment described above.

[0056] When the vibration-damping target equipment 1 vibrates in the Y direction due to seismic motion, the weight 61 vibrates the beam structure 62 (see FIG. 8) so as to cancel the vibration of the vibration-damping target equipment 1. The beam structure 62 is a structure obtained by connecting the first beam-shaped member 51 and the second beam-shaped member 52 with a connecting mechanism 53. The pedestal 38 is disposed at the lower end of the second beam-shaped member 52. The pedestal 58 is a portion for fixing the second beam-shaped member 52 to the damper installation section 14 below the first beam-shaped member 51. The pedestal 58 is fixed to the damper installation section 14 by, for example, a bolt or the like with the pedestal 58 placed on the damper installation section 14.

[0057] (Connection mechanism 53) The connecting mechanism 53 connects the first beam member 51 and the second beam member 52 in a state where they are not constrained in the in-plane direction but are constrained in the out-of-plane direction. Specifically, the connecting mechanism 53 has a rotating member 63. The rotating member 63 is a member for connecting the first beam member 51 and the second beam member 52. The rotating member 63 is also a member for connecting the first beam member 51 and the second beam member 52 in a state where they are not constrained in the in-plane direction but are constrained in the out-of-plane direction by combining with a protrusion 55 provided on the first beam member 51. This will be described in detail below.

[0058] The rotating member 63 is a flat rod-shaped member. A guide rail portion 64 is formed in the rotating member 63. The guide rail portion 64 is formed along the longitudinal direction of the rotating member 63. In addition, an escape groove 65 is formed on the back side of the rotating member 63, as shown in Figs. 9 and 10. The escape groove 65 is formed to have a dimension slightly larger than the guide rail portion 64. The escape groove 65 is formed to avoid interference with the head portion 55a of the bolt serving as the protrusion 55.

[0059] As shown in FIG. 9, one end of the rotating member 63 is rotatably attached to the plate-shaped portion 57 of the second beam member 52 by a rivet member 66. For this reason, a through hole 67 (see FIG. 10) for inserting a body portion 66a of the rivet member 66 is provided at one end of the rotating member 63. The rivet member 66 is a member constituting a rotation fulcrum. A pin 68 is provided at the rotating member 63. The pin 68 is fixed to the rotating member 63 by, for example, press-fitting. The pin 68 is disposed at an end of the rotating member 63 on the opposite side to the rivet member 66 in the longitudinal direction. The pin 68 is inserted into a groove portion 59 as shown in FIG. 9. When the rotating member 63 rotates around the body portion 66a of the rivet member 66 as the rotation fulcrum, the pin 68 moves along the arc-shaped groove portion 59. As a result, the rotating member 63 is provided rotatably around the rivet member 66 along the arc-shaped groove portion 59.

[0060] On the other hand, the male thread portion 55b of the bolt as the protrusion portion 55 is fitted into the guide rail portion 64 of the rotating member 63. The male thread portion 55b of the bolt is movably fitted into the guide rail portion 64 of the rotating member 63. In this case, the male thread portion 55b of the bolt corresponds to the fitting portion. The direction in which the male thread portion 55b moves is the longitudinal direction of the rotating member 63. The head portion 55a of the bolt is in contact with the bottom surface 65a of the clearance groove 65 around the guide rail portion 64. The contact pressure of the head portion 55a against the bottom surface 65a of the clearance groove 65 is set to a pressure such that the male thread portion 55b of the bolt as the protrusion portion 55 is guided by the guide rail portion 64 and can move in the longitudinal direction of the rotating member 63 by appropriately adjusting the tightening torque of the two nuts constituting the double nut structure portion 56. The head portion 55a of the bolt is accommodated in the space formed by the clearance groove 65. In this case, the head 55a of the bolt and the double nut structure 56 form a holding portion that maintains the fitted state between the guide rail portion 64 and the male thread portion 55b of the bolt.

[0061] By configuring the connecting mechanism 53 in this manner, the first beam member 51 and the rotating member 63 are connected by a bolt serving as the protrusion 55 and a double nut structure 56 that engages with the male thread portion 75b of the bolt. In addition, the rotating member 63 and the second beam member 52 are connected by a rivet member 66. For this reason, the relative movement of the first beam member 51 and the second beam member 52 is restricted in the out-of-plane direction.

[0062] Furthermore, the rotating member 63 can rotate along the arc-shaped groove 59 around the body 66a of the rivet member 66, and the bolt serving as the protrusion 55 can move in the longitudinal direction of the rotating member 63 along the guide rail portion 64. For this reason, the relative movement of the first beam member 51 and the second beam member 52 is not restricted in the in-plane direction.

[0063] The mass damper 50 according to the third embodiment of the present invention can match the natural frequency of the mass damper 50 to the natural frequency of the vibration-damping target equipment 1 by setting the Y-directional rigidity of the connecting mechanism 53 low and using a weight 61 with a large mass. As a result, when the vibration-damping target equipment 1 vibrates in the Y-directional direction due to seismic motion, the mass damper 50 vibrates (resonates) so as to cancel out the vibration. Therefore, the vibration energy of the vibration-damping target equipment 1 can be absorbed by the mass damper 50, and the vibration of the vibration-damping target equipment 1 can be reduced.

[0064] In the mass damper 50 according to the third embodiment of the present invention, when the mass damper 50 is installed in the vibration-damping target device 1 having a large mass, a weight 61 having a relatively large mass can be used in accordance with the mass of the vibration-damping target device 1. The weight 61 is attached to the plate-like portion 57 of the second beam member 52, and the base portion 58 of the second beam member 52 is fixed to the damper installation portion 14. Therefore, the mass of the weight 61 is supported by the damper installation portion 14 via the second beam member 52. Therefore, the vibration-damping target device 1 does not need to support the mass of the weight 61. The beam structure portion 62 of the mass damper 50 is configured by connecting the first beam member 51 as a flat plate portion and the second beam member 52 having the plate-like portion 57 as a flat plate portion by the connecting mechanism 53. Therefore, the resonant frequency of the mass damper 50 can be set low.

[0065] Moreover, in the mass damper 50 according to the third embodiment of the present invention, the connecting mechanism 53 does not constrain the first beam member 51 and the second beam member 52 in the in-plane direction. Therefore, when the first beam member 51 moves in the in-plane direction by the same amount as the vibration-damping target equipment 1 due to thermal expansion or thermal contraction of the equipment support member 2 (see FIG. 1), the movement of the first beam member 51 is permitted by the rotational movement of the rotating member 63 about the rivet member 66 and the movement of the protrusion 55 along the guide rail portion 64. Therefore, even if the first beam member 51 moves in the in-plane direction, no excessive force is applied to the connecting mechanism 53. Therefore, damage to the mass damper 50 can be avoided.

[0066] In the mass damper 50 according to the third embodiment of the present invention, the first beam member 51 serving as a flat plate portion and the plate portion 57 of the second beam member 52 are both arranged standing perpendicular to the damper installation portion 14. That is, the mass damper 50 is an upright mass damper. For this reason, the mass damper 50 can be installed in a narrow portion where the installation space is limited.

[0067] <Fourth embodiment> Fig. 11 is an exploded perspective view showing the configuration of a mass damper according to a fourth embodiment of the present invention. Fig. 12 is a cross-sectional view taken along line DD in the assembled state of the mass damper shown in Fig. 11. Fig. 13 is a cross-sectional view taken along line EE in the assembled state of the mass damper shown in Fig. 11. 11 to 13, the mass damper 70 includes a first beam-shaped member 71, a second beam-shaped member 72, and a connecting mechanism 73. The mass damper 70 is installed on the damper installation portion 14.

[0068] (First beam member 71) The first beam member 71 is formed in a flat plate shape overall. In other words, the first beam member 71 itself constitutes a flat plate portion. The first beam member 51 as a flat plate portion is arranged in a state of standing vertically with respect to the damper installation portion 14. The first beam member 51 is also arranged in a direction parallel to the X direction. Therefore, the surface direction of the first beam member 51 is parallel to the XZ plane, and the thickness direction of the first beam member 51 is parallel to the Y direction. When the mass damper 70 is viewed from the front direction, the first beam member 71 is formed in a vertically elongated shape with both ends in the longitudinal direction being rounded. The first beam member 71 is preferably made of a vibration-damping steel plate.

[0069] The first beam member 71 is connected to the tip side of the vibration-damping target equipment 1. Specifically, the upper end side of the first beam member 71 forms a connection part 71a, and this connection part 71a is fixed to the tip side of the vibration-damping target equipment 1 by a plurality of bolts 74 (six in the illustrated example). The plurality of bolts 74 are arranged at appropriate intervals. In addition, the first beam member 71 is fixed to the side surface 1c of the vibration-damping target equipment 1 by the plurality of bolts 74.

[0070] A protrusion 75 is provided on the lower end side of the first beam member 71. The protrusion 75 can be formed of a bolt, for example, as shown in Figs. 12 and 13. In this case, a through hole is provided on the lower end side of the first beam member 71 for inserting a male threaded portion 75b of the bolt as the protrusion 75. A head 75a and a male threaded portion 75b of the bolt as the protrusion 75 protrude to the back side of the first beam member 71. In addition, two nuts constituting a double nut structure portion 76 are engaged with the male threaded portion 55b of the bolt as the protrusion 75, and the bolt as the protrusion 75 is fixed to the first beam member 71 by appropriately adjusting the tightening torque of each nut.

[0071] (Second beam member 72) As shown in FIG. 11, the second beam member 72 has a plate-shaped portion 77 as a flat plate portion and a base portion 78 for fixing the second beam member 72 to the damper installation portion 14. When the mass damper 70 is viewed from the front direction, the plate-shaped portion 77 is formed in a substantially rectangular shape. Of the plate-shaped portion 77 and the base portion 78, at least the plate-shaped portion 77 is preferably made of a vibration-damping steel plate. The plate-shaped portion 77 is arranged in a state in which it stands perpendicular to the damper installation portion 14. The plate-shaped portion 77 is arranged in a direction parallel to the X direction. Therefore, the surface direction of the plate-shaped portion 77 is parallel to the XZ plane, and the thickness direction of the plate-shaped portion 77 is parallel to the Y direction. A pair of vertical grooves 79 is formed in the plate-shaped portion 77. The pair of vertical grooves 79 is provided on the upper end side of the second beam member 72. The pair of vertical grooves 79 are arranged at an appropriate interval in the X direction. The pair of vertical grooves 79 are formed parallel to each other with their major axes aligned in the Z direction. Each vertical groove 79 is formed so as to penetrate the plate-like portion 77 in the thickness direction.

[0072] A weight 81 is attached to the plate-shaped portion 77. The weight 81 is attached at a position at an appropriate distance from the base portion 78. The attachment structure of the weight 81 is similar to the attachment structure of the weight 25 in the first embodiment described above and the attachment structure of the weight 41 in the second embodiment described above.

[0073] When the vibration-damping target equipment 1 vibrates in the Y direction due to seismic motion, the weight 81 vibrates the beam structure 82 (FIG. 11) so as to cancel the vibration of the vibration-damping target equipment 1. The beam structure 82 is a structure obtained by connecting the first beam-shaped member 71 and the second beam-shaped member 72 with a connecting mechanism 73. The pedestal portion 78 is disposed at the lower end of the second beam-shaped member 72. The pedestal portion 78 is a portion for fixing the second beam-shaped member 72 to the damper installation portion 14 below the first beam-shaped member 71. The pedestal portion 78 is fixed to the damper installation portion 14 by, for example, a bolt or the like with the pedestal portion 78 placed on the damper installation portion 14.

[0074] (Connection mechanism 73) The connecting mechanism 73 connects the first beam member 51 and the second beam member 52 in a state where they are not constrained in the in-plane direction but are constrained in the out-of-plane direction. Specifically, the connecting mechanism 53 has a moving member 83. The moving member 83 is a member for connecting the first beam member 71 and the second beam member 72. The moving member 83 is also a member for connecting the first beam member 71 and the second beam member 72 in a state where they are not constrained in the in-plane direction but are constrained in the out-of-plane direction by combining with a protrusion 75 provided on the first beam member 71. This will be described in detail below.

[0075] The moving member 83 is a flat rod-shaped member. A guide rail portion 84 is formed in the moving member 83. The guide rail portion 84 is formed along the longitudinal direction of the moving member 83. In addition, an escape groove 85 is formed on the back side of the moving member 83, as shown in Figs. 12 and 13. The escape groove 85 is formed with a dimension slightly larger than the guide rail portion 84. The escape groove 85 is formed to avoid interference with the head portion 75a of the bolt serving as the protrusion 75.

[0076] The moving member 83 is disposed between the pair of vertical grooves 79. The moving member 83 is attached to the second beam member 72 in a state in which it can move along the pair of vertical grooves 79. Specifically, two guide bolts 86 are attached to the moving member 83. The two guide bolts 86 are disposed at both ends of the moving member 83 in the longitudinal direction. The heads 86a of the guide bolts 86 are accommodated in recesses 83a formed on the front side of the moving member 83. The male threaded portion 86b of the guide bolt 86 is inserted into the vertical groove 79 through a through hole 83b provided in the moving member 83. Two nuts constituting a double nut structure 87 are engaged with the male threaded portion 86b of the guide bolt 86. The moving member 83 is supported so as to be movable in the Z direction along the pair of vertical grooves 79 by appropriately adjusting the tightening torque of the two nuts constituting the double nut structure 87.

[0077] On the other hand, the male thread portion 75b of the bolt as the protrusion portion 75 is fitted into the guide rail portion 84 of the moving member 83. The male thread portion 75b of the bolt is movably fitted into the guide rail portion 84 of the moving member 83. In this case, the male thread portion 75b of the bolt corresponds to the fitting portion. The direction in which the male thread portion 55b moves is the longitudinal direction (X direction) of the moving member 83. The head portion 75a of the bolt is in contact with the bottom surface 85a of the escape groove 85 around the guide rail portion 84. The contact pressure of the head portion 75a against the bottom surface 85a of the escape groove 85 is set to a pressure such that the male thread portion 75b of the bolt as the protrusion portion 75 is guided by the guide rail portion 84 and can move in the longitudinal direction of the moving member 83 by appropriately adjusting the tightening torque of the two nuts constituting the double nut structure portion 76. In this case, the head 75a of the bolt and the double nut structure 76 form a holding portion that maintains the fitted state between the guide rail portion 84 and the male thread portion 75b of the bolt.

[0078] By configuring the connecting mechanism 73 in this manner, the first beam member 71 and the moving member 83 are connected by a bolt serving as the protrusion 75 and a double nut structure 76 that engages with the bolt. The moving member 83 and the second beam member 72 are connected at both ends of the moving member 83 by a guide bolt 86 and a double nut structure 87 that engages with a male thread portion 86b of the guide bolt 86. For this reason, the relative movement of the first beam member 71 and the second beam member 72 is restricted in the out-of-plane direction.

[0079] Furthermore, the guide rail portion 84 is movable in the Z direction along the pair of vertical grooves 79, and the bolt serving as the protrusion 75 is movable in the longitudinal direction of the movable member 83 along the guide rail portion 84. Therefore, the relative movement of the first beam member 71 and the second beam member 72 is not restricted in the in-plane direction.

[0080] Mass damper 70 according to the fourth embodiment of the present invention can match the natural frequency of mass damper 70 to the natural frequency of the vibration-damping target equipment 1 by setting the Y-directional rigidity of beam structure 82 low and using weight 81 with a large mass. As a result, when the vibration-damping target equipment 1 vibrates in the Y-directional direction due to seismic motion, mass damper 70 vibrates (resonates) so as to cancel out this vibration. Therefore, the vibration energy of the vibration-damping target equipment 1 can be absorbed by mass damper 70, and the vibration of the vibration-damping target equipment 1 can be reduced.

[0081] In the mass damper 70 according to the fourth embodiment of the present invention, when the mass damper 70 is installed in the vibration-damping target device 1 having a large mass, a weight 81 having a relatively large mass can be used in accordance with the mass of the vibration-damping target device 1. The weight 81 is attached to the plate-like portion 77 of the second beam member 72, and the base portion 78 of the second beam member 72 is fixed to the damper installation portion 14. Therefore, the mass of the weight 81 is supported by the damper installation portion 14 via the second beam member 72. Therefore, the vibration-damping target device 1 does not need to support the mass of the weight 81. The beam structure portion 82 of the mass damper 70 is configured by connecting the first beam member 71 as a flat plate portion and the second beam member 72 having the plate-like portion 77 as a flat plate portion by the connecting mechanism 73. Therefore, the resonant frequency of the mass damper 70 can be set low.

[0082] Moreover, in the mass damper 70 according to the fourth embodiment of the present invention, the connecting mechanism 73 does not constrain the first beam member 71 in the in-plane direction. Therefore, when the first beam member 71 moves in the in-plane direction by the same amount as the vibration-damping target equipment 1 due to thermal expansion or contraction of the equipment support member 2 (see FIG. 1), the movement of the first beam member 71 is permitted by the movement of the moving member 83 along the pair of vertical grooves 79 and the movement of the protrusion 75 along the guide rail portion 84. Therefore, even if the first beam member 71 moves in the in-plane direction, no excessive force is applied to the connecting mechanism 73. Therefore, damage to the mass damper 70 can be avoided.

[0083] In mass damper 70 according to the third embodiment of the present invention, first beam member 71 serving as a flat plate portion and plate portion 77 of second beam member 72 are both arranged standing perpendicular to damper installation portion 14. In other words, mass damper 70 is an upright mass damper. For this reason, mass damper 70 can be installed in a narrow area with limited installation space.

[0084] <Modifications, etc.> The present invention is not limited to the above-described embodiment, but includes various modified examples. For example, the above-described embodiment has been described in detail to facilitate understanding of the contents of the present invention, but the present invention is not necessarily limited to having all the configurations described in the above-described embodiment. It is also possible to replace a part of the configuration of one embodiment with the configuration of another embodiment. It is also possible to add the configuration of another embodiment to the configuration of one embodiment. It is also possible to delete a part of the configuration of each embodiment, add another configuration, or replace it with another configuration. [Explanation of symbols]

[0085] 1...equipment to be damped, 2...equipment support member, 10...mass damper, 11...first beam member, 11a...connection portion 11a, 12...second beam member, 13...connection mechanism, 14...damper installation portion, 15, 16, 21...plate-shaped portion, 22...base portion, 23...space portion, 25...weight, 30...mass damper, 31...first beam member, 31a...connection portion, 32...second beam member, 33...connection mechanism, 34...through hole, 39...space portion, 40...circular hole, 41...weight, 45...connection member, 46...disc portion, 47...shaft portion, 48...fixed portion, 50...mass damper, 51...first beam member, 51a...connection portion, 52... Second beam member, 53...connection mechanism, 55...projection, 59...groove, 61...weight, 66...rivet member (rotation fulcrum), 63...rotating member, 64...guide rail portion, 55b...male thread portion (fitting portion), 55a...head (holding portion), 56...double nut structure portion (holding portion), 70...mass damper, 71...first beam member, 71a...connection portion, 72...second beam member, 73...connection mechanism, 75...projection, 75b...male thread portion (fitting portion), 79...vertical groove, 81...weight, 83...moving member, 84...guide rail portion, 75a...head (holding portion), 76...double nut structure portion (holding portion)

Claims

1. A mass damper for use with a vibration-damping target device that is supported by an equipment support member and extends from the equipment support member in a first horizontal direction, a first beam member and a second beam member each having a flat plate portion, the flat plate portion standing perpendicular to the damper installation portion, and disposed in a direction parallel to the first horizontal direction; a connecting mechanism that connects the first beam member and the second beam member, the first beam member has a connection portion connected to a tip side of the vibration damping target device, the second beam member has a base portion for fixing the second beam member to a damper installation portion below the first beam member, A weight is attached to the flat plate portion of the second beam member, The load of the second beam member including the weight and the base portion is supported by the damper installation portion. Mass damper.

2. The connecting mechanism connects the first beam member and the second beam member in a state in which the first beam member and the second beam member are not constrained in an in-plane direction that is a direction parallel to the first horizontal direction and the vertical direction, and are constrained in an out-of-plane direction that is a direction parallel to a second horizontal direction perpendicular to the first horizontal direction.

2. The mass damper of claim 1.

3. The effective mass of the weight at the second horizontal resonance frequency is 1 / 20 or more of the effective mass of the vibration damping target device at the second horizontal resonance frequency.

3. The mass damper of claim 2.

4. the first beam member has a plate-like portion disposed on a lower end side of the first beam member opposite to a connection portion with the vibration damping target device, The second beam member has a space portion that is rectangular in front view and is formed on an upper end side of the second beam member, The connecting mechanism connects the first beam member and the second beam member in a state in which the plate-shaped portion is inserted into the space portion that is rectangular in a front view.

3. The mass damper of claim 2.

5. The first beam member has a through hole on a lower end side of the first beam member, The second beam member has a space portion that is circular in front view and is formed on an upper end side of the second beam member, and a circular hole that communicates with the space portion, the connecting mechanism includes a connecting member for connecting the first beam member and the second beam member, The connecting member includes a disk portion having an outer diameter smaller than an inner diameter of the circular space portion when viewed from the front, a shaft portion having an outer diameter smaller than the circular hole and one end connected to a center of the disk portion, and a fixing portion connected to the other end of the shaft portion, the disk portion being inserted into the circular space portion when viewed from the front, the shaft portion being inserted into the through hole and the circular hole, and the fixing portion being configured to fix the connecting member to the first beam member.

3. The mass damper of claim 2.

6. The first beam member has a protrusion provided on a lower end side of the first beam member, The second beam member has an arc-shaped groove portion provided on an upper end side of the second beam member, the connecting mechanism has a rotating member that is rotatably attached to the second beam member with one end as a rotation fulcrum and that is rotatable along the arc-shaped groove portion around the rotation fulcrum; The rotating member has a guide rail portion formed along a longitudinal direction of the rotating member, The protrusion of the first beam member has a fitting portion that is movably fitted into the guide rail portion of the rotating member, and a holding portion that holds the fitted state between the guide rail portion and the fitting portion.

3. The mass damper of claim 2.

7. The first beam member has a protrusion provided on a lower end side of the first beam member, The second beam member has a pair of vertical grooves provided on an upper end side of the second beam member, the connecting mechanism has a movable member disposed across the pair of vertical grooves and attached to the second beam member in a state movable along the pair of vertical grooves, The moving member has a guide rail portion formed along a longitudinal direction of the moving member, The protrusion of the first beam member has a fitting portion that is movably fitted into the guide rail portion of the moving member, and a holding portion that holds the fitted state between the guide rail portion and the fitting portion.

3. The mass damper of claim 2.

Images