JP3751685B2

JP3751685B2 - Cable stayed damper

Info

Publication number: JP3751685B2
Application number: JP17256596A
Authority: JP
Inventors: 俊明榊; 文雄関堂; あけみ川那辺
Original assignee: Sumitomo Rubber Industries Ltd
Current assignee: Sumitomo Rubber Industries Ltd
Priority date: 1996-07-02
Filing date: 1996-07-02
Publication date: 2006-03-01
Anticipated expiration: 2016-07-02
Also published as: JPH1018222A

Description

【０００１】
【発明の属する技術分野】
本発明は斜張橋用ダンパーに関し、詳しくは、斜張橋に架設されたケーブルに対する風や走行車両などによる入力振動を減衰させ、ケーブルが破断するのを防止する斜張橋用ダンパーに関する。
【０００２】
【従来の技術】
一般に、斜張橋は剛性の低い柔構造物であり、斜張橋に架設された複数本のケーブルの耐風安定性がその設計上重要な要素となっている。この風によるケーブルの振動への対処方法としては、ケーブル自体の断面形状を安定化する空力的対策があるが、これ以外にも、近年ではオイルダンパーや粘性剪断型ダンパーがケーブルの有効な制振装置として多用されている。
【０００３】
しかしながら、これらオイルダンパーや粘性剪断型ダンパーは、オイルや粘性体の温度依存性が大きいので、橋面付近に取り付けられる関係上、その橋面温度の影響を受けやすく、使用条件の温度範囲内で性能が不安定となる。また、オイルダンパーや粘性剪断型ダンパーは外付け構造となっているため、ダンパー自体が大掛りになる上に外観的にも斜張橋としての美感を損なう。
【０００４】
そこで、オイルダンパーや粘性剪断型ダンパーに代わるものとして、温度依存性が少なく、外観の良い斜張橋ケーブルの制振装置が提案されている〔特開平７−１１９１１５号公報〕。この制振装置に使用されているダンパーは、図１１に示すように高減衰ゴムの成形体１に上下金具２，３を加硫接着などにより一体的に取り付けた構造を有する。
【０００５】
この成形体１を構成する高減衰ゴムは温度依存性が少ないので、橋面温度の影響を受けにくく、使用条件の温度範囲内での性能の安定化が図れ、また、成形体１を組み込んだ制振装置は、外観的な簡素化を実現したものとなっている。
【０００６】
【発明が解決しようとする課題】
ところで、前述した高減衰ゴムの成形体１からなる斜張橋用ダンパーでは、成形体１の上下金具２，３と接合する端部、即ち、エッジ部４の外周面が上下金具２，３の接合面とほぼ垂直をなすような構造を有しているため、以下のような問題があった。
【０００７】
高減衰ゴムの成形体１は、斜張橋ケーブルに振動が入力されるごとに変形するため、繰り返される変形により成形体１のエッジ部４の高減衰ゴムに疲労が集中してその部分が破壊したり剥がれたりする。また、この高減衰ゴムの疲労集中による破壊でもって成形体１の変形時に特定部分に応力が集中して破壊や剥がれがより一層進行して広がる。更に、成形体１の破壊部分から酸素が侵入して高減衰ゴムの劣化を促進し、ダンパーとしての減衰性能を低下させる。
【０００８】
そこで、本発明は上記問題点に鑑みて提案されたもので、その目的とするところは、ケーブルへの入力振動により高減衰ゴムの成形体が変形を繰り返しても、成形体の上下金具との接合端部が破壊したり剥がれたりすることを可及的に抑制し得る斜張橋用ダンパーを提供することにある。
【０００９】
【課題を解決するための手段】
上記目的を達成するための技術的手段として、本発明は、斜張橋に架設されたケーブルに対する入力振動を減衰させてケーブルが破断するのを防止する斜張橋用ダンパーにおいて、上下金具と一体化された高減衰ゴムの成形体の前記上下金具との接合端部を、前記上下金具に向けて横断面積が漸増し、接合端部の外周面と上下金具の接合面とのなす角度を４５°以下としたことを特徴とする。
【００１０】
【発明の実施の形態】
本発明の実施形態を以下に説明する。尚、本発明の斜張橋用ダンパーは、例えば、特開平７−１１９１１５号公報に開示された斜張橋ケーブルの制振装置に適用される。
【００１１】
本発明の斜張橋用ダンパーは、高減衰ゴムの成形体１１の上下金具１２，１３との接合端部を、その上下金具１２，１３に向けて横断面積が漸増するように成形したものである。具体的には、成形体１１の上下金具１２，１３との接合端部であるエッジ部１４を、図１に示すようなＲ形状としたり、図２に示すような直線テーパ形状としたり、図３に示すような膨出形状とする。
【００１２】
尚、図１及び図２に示すような形状とすることにより、成形体１１の剪断変形時、エッジ部１４への応力集中を可及的に抑制することができる。また、図３に示す形状についても、エッジ部１４の外周面と上下金具１２，１３の接合面とのなす角度θを４５°以下とすれば、成形体１１の剪断変形時、エッジ部１４への応力集中を可及的に抑制することができる。
【００１３】
ここで、図４に示す従来のダンパーでは、その上金具２が図示矢印方向へ動いた時に成形体１のエッジ部４に圧縮応力が作用する。この場合、エッジ部４では、図示矢印方向と直交する圧縮方向に高減衰ゴムが肉厚であるため、非常に大きな圧縮応力が集中することによりエッジ部４での剥離又は破壊が起きやすい。一方、図５に示す本発明のダンパーでは、エッジ部１４で圧縮方向の高減衰ゴムが薄くなるため、高減衰ゴムの逃げる余裕が大きく、エッジ部１４に過大な圧縮応力が集中することはないのでエッジ部１４での剥離又は破壊が起きにくい。
【００１４】
また、図６に示す従来のダンパーにおいて、前述の場合とは反対にその上金具２が図示矢印方向へ動いた時に成形体１のエッジ部４に引張り応力が作用する。この場合、エッジ部４に作用する応力は水平方向ばかりでなく、そのエッジ部４での圧縮方向の高減衰ゴムが肉厚であるため、斜め下方への引張り応力も非常に大きくなり、全体として非常に大きな応力となるのでエッジ部４での剥離又は破壊が起きやすい。一方、図７に示す本発明のダンパーでは、水平方向の引張り応力は同じであるが、エッジ部１４での圧縮方向の高減衰ゴムが薄くなるため、斜め下方への引張り応力が非常に小さくなり、全体として小さな応力となるのでエッジ部１４での剥離又は破壊が起きにくい。
【００１５】
尚、本発明のダンパーにおいて、成形体１１を構成する高減衰ゴムとしては、天然ゴム、ＳＢＲ、ＮＢＲ、ＢＲ、シリコンゴム、ＥＰＤＭ、ブチルゴム等のゴム、又はこれらゴムに充填剤、オイル、カップリング剤を配合したゴム配合物などがある。また、前述した成形体１１の断面形状は円形、角形、菱形、扇形などその形状は問わず、中実の円柱形状や中空の円筒形状であってもよい。更に、成形体１１の高減衰ゴムの外周を耐候性に優れたゴムで被覆するようにすれば、屋外使用にも好適である。
【００１６】
また、前述した実施形態では、本発明のダンパーを、例えば特開平７−１１９１１５号公報に開示された斜張橋ケーブルの制振装置に適用した場合について説明したが、本発明はこれに限定されることなく、斜張橋ケーブルに取り付けられるダンパーとして他の構造にも適用可能であるのは勿論である。
【００１７】
【実施例】
本出願人は、図１乃至図３に示す本発明のダンパー〔実施例１〜３〕と図１１に示す従来のダンパー〔比較例〕とを製作し、これらについて破壊試験を行なった。
【００１８】
成形体１１（１）の高減衰ゴムとしては天然ゴムを使用し、被覆ゴムとしてはブチルゴムを使用した。また、いずれのゴムにも、硫黄、亜鉛華、老化防止剤、加硫促進剤、軟化剤、補強剤及び充填剤を配合した。成形体１１（１）は円柱状に押し出し成形したものであり、被覆ゴムはシート状に押し出し成形したものであり、これら成形体１１（１）、被覆ゴム及び上下金具１２，１３（２，３）を金型にセッティングし、１５０℃で４０分間加硫することにより製作された。尚、上下金具１２，１３（２，３）の成形体１１（１）との接合面には、加硫接着剤を予め塗布しておく。
【００１９】
このダンパーは、成形体１１（１）の高さが２０ｍｍ、直径が５０ｍｍ、被覆ゴムの厚みが２ｍｍであり、実施例１〔Ｒ形状〕では、成形体１１のエッジ部１４について曲率半径Ｒを５ｍｍ〔図８参照〕とし、実施例２〔直線テーパ形状〕では、成形体１１のエッジ部１４について曲率半径Ｒを１０ｍｍ、かつ、直線部分と上下金具１２，１３の接合面となす角度θを３０°とし〔図９参照〕、実施例３〔膨出形状〕では、成形体１１のエッジ部１４について曲率半径Ｒ₁を５ｍｍ、Ｒ₂を１０ｍｍ、かつ、上下金具１２，１３となす角度θを４５°とする〔図１０参照〕。
【００２０】
本出願人が行なった試験では、ダンパーに圧縮歪みを付与せずに剪断歪みのみを付与してどの程度の回数で成形体１１（１）のエッジ部１４（４）に剥離又は破壊が生じるかを調べ、その結果を下表に示す。尚、下表において、歪みは成形体１１（１）のゴム高さに対する歪みであり、１００％は２０ｍｍの変位、５０％は１０ｍｍの変位を付与した時のものでる。また、５０００回ごとに剥離又は破壊の有無を目視確認した。
【００２１】
【表１】

【００２２】
上表から明らかなように実施例１〜３〔本発明品〕では、比較例〔従来品〕と比べて剥離又は破壊が発生しにくくなった。
【００２３】
【発明の効果】
本発明によれば、成形体の上下金具との接合端部を、前記上下金具に向けて横断面積が漸増するように成形したことにより、ケーブルへの入力振動により高減衰ゴムの成形体が変形を繰り返しても、接合端部への応力集中を可及的に抑制し、成形体の上下金具との接合端部が疲労集中して破壊したり剥がれたりすることを可及的に抑制することができ、酸素の侵入などによる高減衰ゴムの劣化を阻止できてダンパーとしての減衰性能を維持できその長寿命化が図れる。
【図面の簡単な説明】
【図１】本発明の実施形態を示す正面図
【図２】本発明の他の実施形態を示す正面図
【図３】本発明の他の実施形態を示す正面図
【図４】従来のダンパーにおいて、成形体のエッジ部に圧縮応力が作用する方向に上金具を動かした状態を示す要部拡大正面図
【図５】本発明のダンパーにおいて、成形体のエッジ部に圧縮応力が作用する方向に上金具を動かした状態を示す要部拡大正面図
【図６】従来のダンパーにおいて、成形体のエッジ部引張り応力が作用する方向に上金具を動かした状態を示す要部拡大正面図
【図７】本発明のダンパーにおいて、成形体のエッジ部に引張り応力が作用する方向に上金具を動かした状態を示す要部拡大正面図
【図８】本出願人が行なった破壊試験に使用した実施例１の成形体のエッジ部を示す図１の要部拡大正面図
【図９】本出願人が行なった破壊試験に使用した実施例２の成形体のエッジ部を示す図２の要部拡大正面図
【図１０】本出願人が行なった破壊試験に使用した実施例３の成形体のエッジ部を示す図３の要部拡大正面図
【図１１】従来の斜張橋用ダンパーを示す正面図
【符号の説明】
１１成形体
１２上金具
１３下金具
１４成形体の上下金具との接合端部〔エッジ部〕[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a cable-stayed bridge damper, and more particularly, to a cable-stayed bridge damper that attenuates input vibration caused by wind or a traveling vehicle with respect to a cable installed on the cable-stayed bridge and prevents the cable from breaking.
[0002]
[Prior art]
Generally, a cable-stayed bridge is a flexible structure with low rigidity, and the wind resistance stability of a plurality of cables installed on the cable-stayed bridge is an important element in the design. There are aerodynamic countermeasures that stabilize the cross-sectional shape of the cable itself as a countermeasure against the vibration of the cable caused by this wind. In recent years, however, oil dampers and viscous shear dampers have been used to effectively control the cable. Widely used as a device.
[0003]
However, these oil dampers and viscous shear type dampers are highly dependent on the temperature of oil and viscous bodies, so they are easily affected by the bridge surface temperature because they are installed near the bridge surface. The performance becomes unstable. In addition, since the oil damper and the viscous shear type damper have an external structure, the damper itself becomes large and the appearance as a cable-stayed bridge is impaired.
[0004]
Therefore, as an alternative to oil dampers and viscous shear dampers, there has been proposed a vibration control device for a cable-stayed bridge cable having a low temperature dependency and good appearance (Japanese Patent Laid-Open No. 7-119115). As shown in FIG. 11, the damper used in this vibration damping device has a structure in which upper and

lower metal fittings

2 and 3 are integrally attached to a molded body 1 of high damping rubber by vulcanization adhesion or the like.
[0005]
Since the high-damping rubber constituting the molded body 1 has little temperature dependency, it is difficult to be affected by the bridge surface temperature, the performance can be stabilized within the temperature range of the use conditions, and the molded body 1 is incorporated. The vibration damping device has realized a simplified appearance.
[0006]
[Problems to be solved by the invention]
By the way, in the cable-stayed bridge damper composed of the molded body 1 of the high-damping rubber described above, the end of the molded body 1 to be joined to the upper and

lower brackets

2 and 3, that is, the outer peripheral surface of the edge portion 4 is the Since the structure is almost perpendicular to the joint surface, there are the following problems.
[0007]
Since the molded body 1 of high damping rubber is deformed every time vibration is input to the cable-stayed bridge cable, fatigue is concentrated on the high damping rubber of the edge portion 4 of the molded body 1 due to repeated deformation, and the portion is destroyed. Or peel off. Further, when the molded body 1 is deformed by the fatigue concentration due to fatigue concentration of the high-damping rubber, stress concentrates on a specific portion, and the destruction or peeling further progresses and spreads. Furthermore, oxygen penetrates from the broken part of the molded body 1 to promote the deterioration of the high-damping rubber, and the damping performance as a damper is lowered.
[0008]
Therefore, the present invention has been proposed in view of the above-mentioned problems, and the object of the present invention is to prevent the molded body of the high-damping rubber from being repeatedly deformed by the input vibration to the cable even if the molded body is repeatedly deformed. It is an object of the present invention to provide a cable-stayed bridge damper capable of suppressing as much as possible the breakage or peeling of the joint end.
[0009]
[Means for Solving the Problems]
As technical means for achieving the above object, the present invention provides a cable-stayed bridge damper to prevent it attenuates the input vibration cable breaks for cables that are laid in the cable-stayed bridge, the upper lower brackets said on joint ends of the lower fitting of the shaped body of the integrated high damping rubber, the cross-sectional area gradually increases toward the upper and lower brackets, the angle of the bonding surface of the outer peripheral surface and the upper and lower brackets of the joint end portion Is 45 ° or less .
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below. The cable-stayed bridge damper of the present invention is applied to a cable-stayed bridge cable damping device disclosed in, for example, JP-A-7-119115.
[0011]
The cable-stayed bridge damper of the present invention is formed by molding the joining end portions of the molded body 11 of high damping rubber with the upper and

lower metal parts

12 and 13 so that the cross-sectional area gradually increases toward the upper and

lower metal parts

12 and 13. is there. Specifically, the edge part 14 which is a joining end part with the upper and

lower metal fittings

12 and 13 of the molded body 11 has an R shape as shown in FIG. 1 or a linear taper shape as shown in FIG. A bulging shape as shown in FIG.
[0012]
In addition, by setting it as a shape as shown in FIG.1 and FIG.2, the stress concentration to the edge part 14 can be suppressed as much as possible at the time of the shear deformation of the molded object 11. FIG. Also, with respect to the shape shown in FIG. 3, if the angle θ formed by the outer peripheral surface of the edge portion 14 and the joint surfaces of the upper and

lower metal members

12, 13 is 45 ° or less, when the molded body 11 is shear-deformed, the edge portion 14 is moved to. Stress concentration can be suppressed as much as possible.
[0013]
Here, in the conventional damper shown in FIG. 4, compressive stress acts on the edge portion 4 of the molded body 1 when the upper metal fitting 2 moves in the direction of the arrow shown in the figure. In this case, at the edge portion 4, the high-attenuating rubber is thick in the compression direction orthogonal to the direction of the arrow shown in the figure. Therefore, peeling or breaking at the edge portion 4 is likely to occur due to the concentration of very large compressive stress. On the other hand, in the damper of the present invention shown in FIG. 5, since the high damping rubber in the compression direction becomes thin at the edge portion 14, there is a large allowance for the high damping rubber to escape, and excessive compressive stress is not concentrated on the edge portion 14. Therefore, peeling or destruction at the edge portion 14 hardly occurs.
[0014]
Further, in the conventional damper shown in FIG. 6, a tensile stress acts on the edge portion 4 of the molded body 1 when the upper metal fitting 2 moves in the direction indicated by the arrow, contrary to the above case. In this case, the stress acting on the edge portion 4 is not only in the horizontal direction, but also because the high-damping rubber in the compression direction at the edge portion 4 is thick, the tensile stress in the diagonally downward direction is very large, and as a whole Since the stress is very large, peeling or breakage at the edge portion 4 is likely to occur. On the other hand, in the damper according to the present invention shown in FIG. 7, the tensile stress in the horizontal direction is the same, but the high-damping rubber in the compression direction at the edge portion 14 becomes thin, so that the tensile stress in the diagonally downward direction becomes very small. Since the stress is small as a whole, peeling or destruction at the edge portion 14 hardly occurs.
[0015]
In the damper of the present invention, as the high damping rubber constituting the molded body 11, natural rubber, rubber such as SBR, NBR, BR, silicon rubber, EPDM, butyl rubber or the like, fillers, oil, couplings to these rubbers are used. There are rubber compounding agents. Moreover, the cross-sectional shape of the molded body 11 described above is not limited to a circular shape, a square shape, a rhombus shape, a fan shape, or a solid cylindrical shape or a hollow cylindrical shape. Furthermore, if the outer periphery of the highly attenuated rubber of the molded body 11 is covered with rubber having excellent weather resistance, it is also suitable for outdoor use.
[0016]
In the above-described embodiment, the case where the damper of the present invention is applied to a vibration control device for a cable-stayed bridge cable disclosed in, for example, Japanese Patent Laid-Open No. 7-119115 has been described. However, the present invention is not limited to this. Of course, the present invention can be applied to other structures as a damper attached to the cable-stayed bridge cable.
[0017]
【Example】
The present applicant manufactured the dampers of the present invention (Examples 1 to 3) shown in FIGS. 1 to 3 and the conventional damper (Comparative Example) shown in FIG. 11 and conducted a destructive test on them.
[0018]
Natural rubber was used as the high damping rubber of the molded body 11 (1), and butyl rubber was used as the covering rubber. Moreover, sulfur, zinc white, an anti-aging agent, a vulcanization accelerator, a softening agent, a reinforcing agent, and a filler were blended in each rubber. The molded body 11 (1) is extruded into a cylindrical shape, and the coated rubber is extruded into a sheet shape. These molded body 11 (1), the coated rubber and the upper and lower metal fittings 12, 13 (2, 3 ) Was set in a mold and vulcanized at 150 ° C. for 40 minutes. A vulcanized adhesive is applied in advance to the joint surfaces of the upper and lower metal members 12 and 13 (2, 3) with the molded body 11 (1).
[0019]
In this damper, the height of the molded body 11 (1) is 20 mm, the diameter is 50 mm, and the thickness of the covering rubber is 2 mm. In Example 1 [R shape], the radius of curvature R of the edge portion 14 of the molded body 11 is set. 5 mm (see FIG. 8), and in Example 2 (linear taper shape), the curvature radius R of the edge portion 14 of the molded body 11 is 10 mm, and the angle θ between the straight portion and the joining surface of the upper and

lower metal members

12 and 13 is 30 ° (see FIG. 9), and in Example 3 (bulging shape), the angle θ formed between the curvature radius R ₁ of the edge portion 14 of the molded body 11 is 5 mm, R ₂ is 10 mm, and the upper and

lower brackets

12 and 13 are formed. Is 45 ° [see FIG. 10].
[0020]
In the test conducted by the present applicant, only the shear strain is applied to the damper without applying the compressive strain, and how many times the edge portion 14 (4) of the molded body 11 (1) peels or breaks. The results are shown in the table below. In the table below, the strain is the strain with respect to the rubber height of the molded body 11 (1). 100% is a displacement when 20 mm is applied, and 50% is when a displacement of 10 mm is applied. Moreover, the presence or absence of peeling or destruction was visually confirmed every 5000 times.
[0021]
[Table 1]

[0022]
As is apparent from the above table, in Examples 1 to 3 [product of the present invention], peeling or breakage was less likely to occur than in the comparative example [conventional product].
[0023]
【The invention's effect】
According to the present invention, the molded end of the high-damping rubber is deformed by the input vibration to the cable by forming the joint end of the molded body with the upper and lower metal fittings so that the cross-sectional area gradually increases toward the upper and lower metal fittings. even after repeated, as much as possible suppress stress concentration to the joint end portion, the joint end portions of the upper and lower bracket formed feature is suppressed as much as possible from being peeled off or destroyed by fatigue concentrate that Therefore, it is possible to prevent deterioration of the high-damping rubber due to oxygen intrusion, etc., and to maintain the damping performance as a damper, thereby extending its life.
[Brief description of the drawings]
FIG. 1 is a front view showing an embodiment of the present invention. FIG. 2 is a front view showing another embodiment of the invention. FIG. 3 is a front view showing another embodiment of the invention. Fig. 5 is an enlarged front view of the main part showing the state in which the upper metal fitting is moved in the direction in which the compressive stress acts on the edge portion of the molded body. Fig. 5 shows the direction in which the compressive stress acts on the edge portion of the molded body in the damper of the present invention. Fig. 6 is an enlarged front view of the main part showing the state in which the upper metal part is moved. Fig. 6 is an enlarged front view of the main part showing the state in which the upper metal part is moved in the direction in which the tensile stress at the edge of the molded body acts. 7 is an enlarged front view of the main part showing the state in which the upper metal fitting is moved in the direction in which tensile stress acts on the edge of the molded body in the damper of the present invention. FIG. 8 is an implementation used for the destructive test conducted by the applicant. The main part expansion of FIG. 1 which shows the edge part of the molded object of Example 1 FIG. 9 is an enlarged front view of the main part of FIG. 2 showing the edge portion of the molded body of Example 2 used in the destructive test conducted by the applicant. FIG. 10 is used for the destructive test conducted by the applicant. 3 is an enlarged front view of the main part of FIG. 3 showing the edge portion of the molded body of Example 3. FIG. 11 is a front view of a conventional cable-stayed bridge damper.
DESCRIPTION OF SYMBOLS 11 Molded body 12 Upper metal fitting 13 Lower metal fitting 14 Joining edge part (edge part) with the upper and lower metal fittings of a molded object

Claims

Attenuates the input vibration for bridging the cable to the cable-stayed bridge in cable-stayed bridge damper to prevent the cable is broken, and the upper lower metal member of the shaped body of high damping rubber which is integrated with the top and bottom brackets A cable-stayed bridge damper, characterized in that a cross-sectional area gradually increases toward the upper and lower metal fittings, and an angle between the outer peripheral surface of the joint end and the joint surface of the upper and lower metal fittings is 45 ° or less. .