JP4883740B2 - Vibration control device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vibration control device for cable-stayed bridge cables, parallel cables, suspension bridge cables, poles, columns, street lights, road lights, traffic lights, lightning rods, chimneys, and other structures.
[0002]
[Prior art]
Hereinafter, the prior art will be described by taking as an example a cable damping device using a cable-stayed bridge cable used for a cable-stayed bridge as a damping member. FIG. 11A shows an outline of a cable-stayed bridge, in which 1 is a bridge girder, 2 is a tower, 3 is a cable-stayed bridge cable, and 4 is a cable damping device. The cable damping device 4 attenuates the vibration of the cable-stayed bridge cable 3 due to the influence of wind, traveling vehicles, etc., reduces the load applied to the cable-stayed bridge cable 3, and prevents the cable-stayed bridge cable 3 from being damaged. It is.
[0003]
As shown in FIGS. 11 (b) and 11 (c), the cable damping device 4 is a rubber damper made of rubber having a damping property, which is a kind of viscoelastic body, in the vicinity of the cable fixing portion 11 attached to the bridge girder 1. 12 is arranged around the cable stayed bridge cable 3 in a uniform manner, one end of the rubber damper 12 is attached to the cable fixing unit 11 side, and the other end is fixed to the cable stayed bridge cable 3 side. And is covered with a cover 13 to shield ultraviolet rays. As shown in FIG. 11 (d), the rubber damper 12 is attached by attaching a steel plate attachment plate 14 bonded to one end of the rubber damper 12 to a flange 16 fixed to the fixing ring 15 at the upper end of the cable fixing portion 11. A steel plate attachment plate 17 bonded to the other end of the rubber damper 12 is attached to a holder 19 fixed to the cable-stayed bridge cable 3 with a clamp ring 18.
[0004]
According to this cable damping device 4, the rubber damper 12 is elastically deformed in the shear direction by receiving the vibration energy of the cable-stayed bridge cable 3 that vibrates due to the influence of wind and the like, and the vibration is attenuated by the reaction force in the shear direction. Thus, the vibration of the cable stayed bridge cable 3 is suppressed.
[0005]
The above vibration damping device attenuates vibrations by the reaction force in the shearing direction of the rubber damper 12 that receives vibration energy and deforms in the shearing direction. In general, in the case of a rubber body made of the same material and having the same cross-sectional area, the longitudinal elastic modulus E (σ / ε) that is the elastic modulus in the tensile direction and the transverse elastic modulus G (τ / γ) that is the elastic modulus in the shear direction. The ratio (E: G) is approximately 3: 1. From this, general rubber bodies are more deformed when the same value of stress is applied in the tension (compression) direction and when the stress is applied in the shear direction. There is. In other words, a general rubber body has a property that the shear direction is softer than the tension (compression) direction.
[0006]
For this reason, the rubber damper 12 is disposed so that the rubber damper 12 is elastically deformed in the shearing direction with respect to the radial displacement of the cable-stayed bridge cable 3 as in the vibration damping device 4 described above.
[0007]
However, since the relationship between the shear strain of the rubber damper 12 and the reaction force when subjected to the shear strain is almost linear until the rubber damper 12 breaks, as shown in FIG. When an abnormally large force is applied to the cable-stayed bridge cable 3, the rubber damper 12 may be damaged beyond the elastic deformation region without sufficiently exerting the reaction force accompanying the shear strain. There is sex.
[0008]
[Problems to be solved by the invention]
Therefore, as a result of various studies on the shape of the vibration damping member, the present applicant has previously found that the vertical cross-sectional shape along the axis of the cable has a V-shape having a hypotenuse that extends vertically from the top to a pair of two forks. A damping member, an alphabetic D-shaped damping member having a flat portion that extends from the arcuate top to a pair of symmetrical arcuate parts and that joins the ends of the arcuate parts, a pair of circles from the apex Proposed a damping device using a damping member having an arc-shaped portion extending, a bottom portion to which the other end portions of the arc-shaped portions are coupled, a drum-shaped outer shape, and a rugby ball-shaped hole inside.
[0009]
The above-described vibration damping device proposed by the present applicant has an excellent initial reaction force and a large margin for compressive deformation as compared with a conventional vibration damping device using a rubber damper having a circular cross section. Although it has vibration performance, if it is difficult to give a strong point, the non-linearity is strong in the low strain region, so there is a weak point in the predictability of the spring constant. In addition, since the direction of compression of the damping member is directional, there is a problem that the damping characteristic varies depending on the compression direction.
[0010]
Therefore, the present invention not only has high vibration damping properties, but also has a damping region for compressive (tensile) stress that is larger than the conventional one, and a constant spring constant in a wide strain region from a low strain region. An object of the present invention is to provide a vibration damping device that includes a vibration damping member and that is easy to design and handle.
[0011]
[Means for Solving the Problems]
The vibration damping device according to claim 1 is provided with a rubber damper that receives vibration energy and elastically deforms in a shear direction on the outer periphery of the vibration-damped member, and attenuates the vibration by a reaction force in the shear direction. in the vibration damping device comprising a damper housing for supporting the enclosing rubber damper, a space portion surrounded by said rubber damper and the object to be vibration damping member, the rubber damper, between the object vibration damper and the damper housing have the shape central axis in a direction extending, which has a rotationally symmetric shape with respect to the central axis, an inner surface of the rubber damper is characterized in that have a continuous curved surface portion.
[0012]
Here, the above-mentioned “space part” facilitates the deformation of the damping member, and the cross-sectional shape thereof is preferably an arc shape . According to such a shape, there is a large deformation margin with respect to the tensile force acting on the vibration damping member disposed on the side opposite to the vibration damping member that receives compressive strain, and while the degree of freedom of deformation is high, The linearity of compressive stress versus strain characteristics is also high. According to the above damping device, a substantially constant spring constant can be obtained over a wide range, the linearity of deformation of the damping member with respect to stress is increased, and vibration of the damping member can be effectively suppressed. .
[0013]
According to the above vibration damping device, the shape of the rubber damper is elastically deformed by the space when stress is applied, and has a shape central axis in a direction extending between the vibration-damped member and the damper housing. In addition, by being configured to have a rotationally symmetric shape with respect to the central axis, the rubber damper spring constant becomes nearly linear in a wide range from a relatively small stress load to a large stress load. The amount of deformation with respect to the stress is constant, and the mounting superiority that enables stable mounting can be increased.
[0014]
The vibration damping device according to a second aspect is characterized in that the rubber damper has a truncated cone shape continuous in the circumferential direction and has a flat top portion.
[0015]
According to the above vibration damping device, since the rubber damper is in the shape of a truncated cone that is continuous in the circumferential direction, any direction relative to the vibration- damped member (as compared to a rubber damper having a rectangular cross-sectional shape in the past) A certain damping characteristic can be obtained even with respect to stress from an angle in a plane perpendicular to the axis.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a vibration damping device 30 according to an embodiment of the present invention using a cable-stayed bridge cable as a vibration-damped member will be described with reference to the drawings.
[0019]
FIG. 1 is a longitudinal sectional view in the axial direction of a vibration damping device 30 attached to a cable-stayed bridge cable 3 as a vibration-damped member, and FIG. 2A is a cross-sectional view taken along line A- perpendicular to the axial direction in FIG. It is a cross-sectional view along the A line. 1 and 2A, 31 is a cable flange fixed to the cable-stayed bridge cable 3, 32 is a rubber damper as a damping member, and 33 is an inner peripheral surface 33a opposite to the outer peripheral surface 31a of the cable flange 31. A damper housing 34 having a polygonal cylinder shape arranged so as to prevent deformation of the damper housing 33, a restraining ring mounted on the outer peripheral surface of the damper housing 33, 35 a centering flange, 36 a fixing flange, and 37 a fixing flange An anchor bolt for fastening 36 to the bridge girder 1 and a cable insertion pipe 38 for allowing the cable stay 1 to pass the cable-stayed bridge cable 3 to each other.
[0020]
The cable flange 31 is a flange member fixed to the cable-stayed bridge cable 3. The damper housing 33 is a bottomed polygonal cylindrical member (octagonal in the illustrated example) disposed so that the inner peripheral surface 33 a faces the outer peripheral surface 31 a of the cable flange 31. A hole 33b through which the bridge cable 3 is inserted is formed.
[0021]
The aligning flange 35 and the fixing flange 36 are for adjusting the positions in the radial direction and the circumferential direction to attach the damper housing 33 to the bridge girder 1. The load applied to the cable-stayed bridge cable 3 is reduced.
[0022]
As shown in FIGS. 3A to 3C, the fixing flange 36 is a set of cylindrical members divided in half along the diameter, and flange plates 36a and 36b are provided at both ends in the axial direction. Is provided. The flange plate 36a on the bridge girder 1 side is formed with a long hole 36c in the circumferential direction, and the long hole 36c is inserted and fastened to an anchor bolt 37 attached to the bridge girder 1. The mounting position of the damper housing 33 is set as the bridge girder. 1 is adjusted in the circumferential direction. A flange plate 36b on the alignment flange 35 side of the fixing flange 36 is formed with a hole 36d centering on a position a decentered with respect to the outer shape, and a plurality of them are planted at predetermined positions along the hole 36d. A stud bolt 36e for mounting the centering flange is provided.
[0023]
Fixing flange 36, as indicated by the two-dot chain line 3 ^'in FIG. 3 (c), when in the position in which stayed bridge cable 3 is shifted from the position of the center of the cable insertion tube 38, in the circumferential direction of the bridge girder 1 side Since the elongated hole 36c is formed, the fixing flange 36 is rotated by a predetermined amount, and the center of the hole 36d formed in the flange plate 36b on the aligning flange 35 side is aligned with the eccentric direction of the cable-stayed bridge cable 3 to be anchored. Fasten to bridge girder 1 with bolts 37.
[0024]
As shown in FIGS. 4A and 4B, the aligning flange 35 is a set of disk-shaped members divided in half along the diameter, and allows the cable-stayed bridge cable 3 to have a sufficient margin. It has a hole 35a that can be loosely fitted and a long hole 35b in which the stud bolt 36e of the fixing flange 36 is slidably fitted. The elongated hole 35b is formed by aligning in the eccentric direction of the hole 36d of the fixing flange 36. The aligning flange 35 is inserted with the stud bolt 36e of the fixing flange 36 into the elongated hole 35d, and is positioned and fastened with a nut so that the cable-stayed bridge cable 3 becomes the center of the aligning flange 35.
[0025]
The rubber damper 32 is a rubber damping member made of a polymer elastic material having a high damping property (for example, the loss coefficient tan δ is larger than 0.30). As shown in b), the whole is a truncated cone-shaped cylindrical body having a small inclined conical portion 32a, a large inclined conical portion 32b, a planar top portion 32c, and a lower end of the large inclined conical portion 32b. A flange 32d extending outward from the flange 32d, a plurality of recesses 32e for accommodating steel plate mounting plates 32g at equal circumferential positions on the upper surface of the flange 32d, and the flange 32d connected to the cable flange 31. A mounting hole 32f for mounting with a mounting bolt on the outer peripheral surface 31a. The mounting plate 32g also has a mounting hole 32h at a position coinciding with the mounting hole 32f of the recess 32e of the flange portion 32d.
[0026]
Specifically, as shown in FIG. 5B, the cross-sectional shape of the rubber damper 32 has a space portion 32j having a continuous curved surface portion 32i on the inner surfaces of the large inclined conical cylindrical portion 32b and the flat top portion 32c. is doing.
[0027]
In the illustrated rubber damper 32, the mounting plate 32g is accommodated in the recess 32e on the upper surface side (conical cylindrical portions 32a, 32b side) of the flange portion 32d, and the flange portion 32d is cable flanged with bolts from above the mounting plate 32g. 31 is attached to the outer peripheral surface 31a. For this reason, it is desirable to form the outer peripheral surface 31a of the cable flange 31 so as to have a rectangular or polygonal flat portion as shown in FIG.
[0028]
The opposite side of the rubber damper 32, that is, the flat top portion 32c side, is in direct contact with the inner peripheral surface 33a of the damper housing 33 or fixedly connected with an adhesive. For this reason, it is desirable to form the inner peripheral surface 33a of the damper housing 33 so as to have a polygonal plane portion as shown in FIG.
[0029]
As a result, the rubber damper 32 can be used in the case where the cable stayed bridge cable 3 is compressed by vibration in the radial direction as shown in FIG. 6B from the no-load state shown in FIG. Under the vibration energy of the bridge cable 3 and the reaction force of the damper housing 33, the conical cylindrical portion 32b is elastically deformed and bulges outward. As shown in FIG. 6C, the rubber damper 32 is elastically deformed to the extent that the space 32j surrounded by the conical tubular portion 32b is almost eliminated. It can sufficiently withstand a compressive deformation corresponding to a compressive strain of about 60% in the radial direction, and can absorb a larger displacement of the cable-stayed bridge cable 3.
[0030]
FIG. 7 shows the relationship between the amount of compression of the cable-stayed bridge cable 3 in the radial direction and its reaction force. As shown by the chain line B in FIG. 7, the conventional rubber damper having a V-shaped cross-section has a linearity within a narrow range of about 50% compression deformation and a compression amount of 0 to 10%. On the other hand, this rubber damper 32 is capable of compressive deformation of about 60% and linearity in a wide range of 0 to 35% as shown by the solid line A in FIG. And has excellent linearity.
[0031]
That is, the rubber damper 32 is compressed and strained by about 0 to 20% due to the vibration of the cable-stayed bridge cable 3, but can sufficiently absorb the vibration energy of the cable-stayed bridge cable 3 within the rubber damping capacity. Moreover, it is excellent also in the elastic compressible deformation region, and can exhibit an excellent vibration damping effect.
[0032]
That is, in the vibration damping device 30, the rubber damper 32 can absorb the vibration of the ordinary cable-stayed bridge cable 3 within the attenuation region in the deformation and exhibit sufficient durability and an excellent vibration damping function. Even when an abnormally large displacement occurs in the cable-stayed bridge cable 3, the tolerance for radial compression deformation is large, the possibility of structural damage is low, and the cable-stayed bridge cable 3 is not subject to an abnormal displacement. As a result, the cable staying bridge cable 3 can be restrained by exerting a larger reaction force.
[0033]
Further, the rubber damper 32 has a circular truncated cone shape, and thus has a rotationally symmetric shape. When the rubber damper 32 is attached to the cable flange 31 and the damper housing 33, the attachment direction thereof is taken into consideration as in the case of the conventional rectangular damper. It is not necessary to do so, and the mounting workability is remarkably improved.
[0034]
In addition, as described above, the rubber damper 32 has a circular truncated cone shape, and thus has a rotationally symmetric shape. If the direction is perpendicular to the central axis, as shown in FIG. However, since the same deformation occurs, the directionality to compression is lost.
[0035]
As mentioned above, although one Embodiment of this invention was described, it is not limited to said embodiment, A various deformation | transformation is possible. For example, in the above embodiment, the rubber damper 32 has been described with respect to the case where the steel plate mounting plate 32g is disposed on the upper surface side (conical cylindrical portions 32a, 32b side) of the flange portion 32d. The mounting plate 32g may be disposed on the side opposite to the conical cylindrical portions 32a and 32b.
[0036]
Further, like the rubber damper 40 shown in FIG. 9, the mounting plate 40g may be embedded in the flange portion 40d. In this way, when the rubber damper 40 is attached, the rubber damper 40 and the attachment plate 40g are not separated, and the attachment workability is further improved.
[0037]
Furthermore, in the above-described embodiment, the case where the flat top portion 32c (40c) is provided and the inner surface of the rubber damper 32 (40) is formed in the arc-shaped curved surface portion 32j (40j) has been described. Like the rubber damper 41 shown in FIG. 10, while having an opening part in the top part 41c, you may form an inner surface in the polygonal shape by the cylindrical part 41k and the conical part 41m. In such a rubber damper 41, a steel plate attachment plate 41n may be attached or embedded in the annular top portion 41c.
[0038]
Further, in the case of the embodiment shown in FIG. 1 and FIG. 2A, the rubber damper 32 has its flange portion 32d on the outer peripheral surface 31a side on the cable flange 31 side, and its flat top portion 32c on the damper housing 33. Although the case where it arrange | positions to the inner peripheral surface 33a side of this was demonstrated, as shown in FIG.2 (b) contrary to the above, the flange part 32d side is set to the inner peripheral surface 33a side of the damper housing 33, and its flat form The top 32c side of the cable flange 31 may be arranged on the outer peripheral surface 31a side of the cable flange 31.
[0039]
Moreover, although the said embodiment demonstrated the case where four rubber dampers 32 (40, 41) were arrange | positioned around the cable-stayed bridge cable 3, the number of arrangement | positioning other than that may be sufficient. However, rubber dampers are arranged on both sides of the cable stayed bridge cable 3 in the diameter direction. By doing so, when the rubber damper on one side receives a compressive stress, the rubber damper on the other side receives a tensile stress and performs a balanced vibration damping action.
[0040]
Furthermore, in the above-described embodiment, the vibration control device for the cable stayed bridge cable has been described. However, the present invention is not limited to the cable stayed bridge cable, but the suspension bridge cable, the parallel cable, the pole, the column, the streetlight, the street light, the traffic light, the lightning rod, the chimney The present invention can be widely applied as a vibration damping device for structures involving other vibrations.
[0041]
【Effect of the invention】
In the vibration damping device of the present invention, a rubber damper that receives vibration energy and elastically deforms in the shearing direction and attenuates the vibration by a reaction force in the shearing direction is disposed on the outer periphery of the vibration-damped member. in the vibration damping device comprising a damper housing enclosing to support, the rubber damper and the has a space portion surrounded by the target damping member, the rubber damper extending between the object vibration damper and the damper housing It has the shape central axis in a direction, which has a rotationally symmetric shape with respect to the central axis, from the inner surface of the rubber damper is to have a continuous curved surface portion, compared with the conventional vibration control device Thus, the linearity of the reaction force with respect to the compression amount is improved, the spring constant is constant from the low strain region to the wide strain region, and the design and handling of the vibration damping device becomes easy. Moreover, since the directionality at the time of the attachment is lost, the attachment workability is remarkably improved. Furthermore, the same deformation is performed for stress from any direction.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view along an axis of a vibration damping device according to an embodiment of the present invention;
2A is a cross-sectional view along the line AA perpendicular to the axis in the vibration damping device of FIG.
(B) is a cross-sectional view perpendicular to the axis of a vibration damping device according to another embodiment of the present invention.
FIG. 3A is a bottom view of the fixing flange of the present invention,
(B) is a side view of the fixing flange,
(C) is a plan view of the fixing flange.
FIG. 4 (a) is a side view of the alignment flange of the present invention,
(B) is a top view of the alignment flange.
FIG. 5A is an enlarged perspective view of a vibration damping member in the vibration damping device according to the embodiment of the present invention;
(B) is an enlarged longitudinal sectional view of the vibration damping member of (a).
FIG. 6A is an enlarged longitudinal sectional view showing a state in which the vibration damping member of the vibration damping device according to the embodiment of the present invention is not compressed;
(B) is an enlarged longitudinal sectional view showing a state where the vibration damping member is compressed halfway;
(C) is an enlarged longitudinal sectional view showing a state in which the damping member is almost completely compressed.
FIG. 7 is a diagram showing a relationship between a compression amount and a reaction force of a vibration damping device according to an embodiment of the present invention, together with a conventional vibration damping device.
FIG. 8 is a plan view of a vibration damping member showing that there is no directionality of stress with respect to the vibration damping member of the vibration damping device according to the embodiment of the present invention.
FIG. 9 is an enlarged longitudinal sectional view of a vibration damping member according to another embodiment of the present invention.
FIG. 10 is an enlarged longitudinal sectional view of a vibration damping member according to still another embodiment of the present invention.
FIG. 11A is a schematic diagram of a general cable-stayed bridge cable;
(B) is a sectional side view of a conventional cable-stayed bridge cable damping device;
(C) is a cross-sectional view of the vibration damping device of (b),
(D) is an enlarged longitudinal sectional view of a vibration damping member portion.
FIG. 12 is a diagram showing the relationship between shear strain and reaction force of a conventional damping member.
[Explanation of symbols]
3 Cable-stayed bridge cable 30 Damping device 31 Cable flange 32, 40, 41 Damping member (rubber damper)
32a, 40a, 41a Small inclined cone portions 32b, 40b, 41b Large inclined cone portions 32c, 40b, 41c Top portions 32d, 40d, 41d Flange portions 32g, 40g, 41g, 41n Mounting plates 32i, 40i Curved portions 32j, 40j , 41j Space portion 33 Damper housing 34 Restraint ring 35 Alignment flange 36 Fixing flange 41k Cylindrical portion 41m Conical portion

Claims (2)

A damper housing that elastically deforms in the shearing direction by receiving vibration energy and dampens vibration by a reaction force in the shearing direction on the outer periphery of the vibration-damped member, and encloses and supports the rubber damper. In the damping device provided,
The rubber damper includes a space surrounded by the rubber damper and the vibration-damping member, and the rubber damper has a central axis in a direction extending between the vibration-damping member and the damper housing. vibration damping device which has a rotationally symmetric shape, the inner surface of the rubber damper, characterized in that have a continuous curved surface portion against.   2. The vibration damping device according to claim 1, wherein the rubber damper has a truncated cone shape continuous in a circumferential direction and has a flat top portion.

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