JP4288766B2 - Vibration control structure of overhead crane - Google Patents

Description

Ｈ：ガーダの高さ寸法
である。
【００２７】
ダンパ作動量δ₁は
【数３】

である。
【００２８】
また、減衰比ζは
【数４】

Δｅ：減衰エネルギー
ｅ：振動系の全エネルギー
Ｃ：ダンパ減衰容量
Ｋ：クレーン撓み剛性
ω：固有角振動数
ｍ：クレーン撓み振動モードの有効質量
Ｘ：クレーン撓み量
δ₁：ダンパ作動量
である。
【００２９】
一方、図８に示すように上下振動によってガーダ２が下側に湾曲したときには、仕切り板８，８間の距離ｌが、上側と下側とで変化するので、仕切り板８，８の上部間と下部間とに水平方向の距離の変化を抑制するダンパＤを設けて制振する方法がある。
【００３０】
このような水平方向のダンパＤを設けた場合のダンパ作動量δ₂は、
【数５】

である。
【００３１】
従って、この水平方向のダンパＤを設けた場合のダンパ作動量δ₂を、本発明の図２に示したダンパ１３，１４の場合のダンパ作動量δ₁と比較すると
【数６】

となる。
【００３２】
通常は、ガーダ２の高さ寸法Ｈより仕切り板間距離ｌのほうが大きく、Ｈ＜ｌであるので、本発明の方がダンパ作動量が大きくなる。
【００３３】
このように、ダンパ作動量が大きいと、ダンパ１３，１４による制振効果を容易に高めることができ、よって特殊なダンパを用いることなしに従来から一般的に用いられているダンパを利用しても、大きな減衰力が得られ、鉛直方向の振動が効果的に抑制できるようになる。
【００３４】
尚、本発明は上記形態例にのみ限定されるものではなく、ダンパ支持部材の形状は種々変更し得ること、種々のダンパが採用できること、その他本発明の要旨を逸脱しない範囲内において種々変更を加え得ること、等は勿論である。
【００３５】
【発明の効果】
本発明によれば、仕切り板の上下中間位置に横方向に延びるダンパ支持部材を固定し、このダンパ支持部材の先端と、上板材及び下板材との間に、上下方向の振動を抑制するダンパを設けた構成としているので、上下振動によってガーダが上下に湾曲したときのダンパ作動量を大きくとることができ、よって、特殊なダンパを用いることなしに従来から一般的に用いられているダンパを利用しても、大きな減衰力が得られ、小型の装置にて上下方向の高い耐震性と高い信頼性とを備えた天井クレーンの制振構造を安価に提供できる効果がある。
【図面の簡単な説明】
【図１】本発明の天井クレーンの制振構造の形態の一例を示す正面図である。
【図２】図１のガーダの一部を拡大して示した正面図である。
【図３】図２のガーダが曲った状態を示す正面図である。
【図４】図１のＩＶ−ＩＶ方向拡大矢視図である。
【図５】ダンパの一例を示す正面図である。
【図６】曲ったガーダの応力と撓みを説明するための線図である。
【図７】本発明のダンパ作動量を説明するための線図である。
【図８】本発明とは異なるダンパ設置方式の場合におけるダンパ作動量を説明するための正面図である。
【図９】従来の天井クレーンの制振構造の一例を示す正面図である。
【図１０】上下振動によってガーダが上下に撓む状態を示した正面図である。
【符号の説明】
１ レール
２ ガーダ
６ 上板材
７ 下板材
８ 仕切り板
９ 縦梁
１０ ダンパ支持部材
１１ 横材
１２ 斜材
１３ ダンパ
１４ ダンパ[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a vibration damping structure for an overhead crane that is installed on a ceiling of a structure such as a factory or a nuclear reactor building and performs indoor cargo handling.
[0002]
[Prior art]
In factories and the like, an overhead crane for carrying cargo indoors is often installed, and such an overhead crane generally has a structure as shown in FIG.
[0003]
The overhead crane shown in FIG. 9 is constructed such that a girder 2 having a rectangular cross section and hollow inside is movably bridged between a pair of rails 1 and 1 fixed near an indoor ceiling via a traveling wheel 3. 2, a trolley 5 provided with a lifting hook 4 is provided so as to be able to travel along the longitudinal direction of the girder 2. The girder 2 is formed with a hollow interior by an upper plate member 6, a lower plate member 7, and left and right vertical beams 9, and the girder 2 is divided into a plurality of partitions along the length direction. A plate 8 is provided.
[0004]
Driving the traveling wheels 3 at both ends by driving means (not shown) provided on the side of the girder 2 causes the girder 2 to travel in a direction perpendicular to the paper surface of FIG. 9, and the trolley 5 is indicated by an arrow along the girder 2. It is possible to move the position of the lifting / lowering hook 4 to an arbitrary position on a plane formed between the rails 1 and 1.
[0005]
[Problems to be solved by the invention]
However, since the above-described overhead crane is supported only by the traveling wheels 3 at both ends of the girder 2 riding on the rails 1, 1, a vertical earthquake acts and a large shake is applied in the vertical direction. When the response increases, the damping ratio in the vertical direction is small, so that the central portion is greatly bent as shown in FIG. 10, and the traveling wheel 3 may be lifted from the rails 1 and 1 and detach from the wheel. There is.
[0006]
Therefore, conventionally, it has been considered to attach a clamp tool for preventing detachment, a hook (not shown) or the like to both ends of the girder 2, but in this case, the clamp tool is caused by the vertical swing of the girder 2. In addition, excessive stress is applied to the hook and the rail side, and the fixing portion is damaged, and the structure (building) supporting the rail is curved.
[0007]
The present invention has been made to effectively solve such a conventional problem, and has a small structure and a large seismic isolation load resistance to suppress the vibration of the overhead crane, so that the traveling wheel is detached from the rail. The object is to provide a vibration control structure of an overhead crane that can prevent problems.
[0008]
[Means for Solving the Problems]
The present invention provides an internal hollow girder having an upper plate member, a lower plate member, and left and right vertical beams that are movably stretched between rails fixed to a ceiling, and a plurality of partitions that divide the inside along the length direction. In an overhead crane equipped with a partition plate, a damper support member extending in the lateral direction is fixed at an intermediate position between the top and bottom of the partition plate, and vibration in the vertical direction is generated between the tip of the damper support member and the upper and lower plate materials. The present invention relates to a vibration damping structure for an overhead crane, which is provided with a damper to be suppressed.
[0009]
In the above means, the damper support member is composed of a cross member extending in the lateral direction from the upper and lower intermediate positions of the partition plate, and a diagonal member connecting between the upper end portion and the lower end portion of the partition plate and the front end portion of the cross member. It may be.
[0010]
According to the present invention, the damper support member that extends in the lateral direction is fixed to the upper and lower intermediate positions of the partition plate, and the damper that suppresses the vibration in the vertical direction between the tip of the damper support member and the upper plate material and the lower plate material. Therefore, it is possible to increase the amount of operation of the damper when the girder bends up and down due to vertical vibrations. Therefore, the damper generally used from the past can be used without using a special damper. Even when used, a large damping force can be obtained, and a small device can be provided with high vertical earthquake resistance and high reliability.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the drawings.
[0012]
1 to 4 show an example of the form of the vibration suppression structure for an overhead crane according to the present invention. In the figure, the same elements as those in FIG.
[0013]
The overhead crane includes an internal hollow girder 2 that is freely run between rails 1 and 1 fixed to the ceiling. The girder 2 includes an upper plate member 6 and a lower plate member as shown in FIG. 7 and left and right vertical beams 9 are formed in a rectangular cross-sectional shape, and a plurality of partition plates 8 are provided in the inside thereof along the length direction.
[0014]
In the above-described overhead crane, a damper support member 10 extending in the lateral direction is fixed to the upper and lower intermediate positions of the partition plate 8 so that the tip approaches the adjacent partition plate 8.
[0015]
The damper support member 10 shown in FIG. 2 and FIG. 3 includes a cross member 11 extending in the lateral direction from the upper and lower intermediate positions of the partition plate 8, an upper end portion and a lower end portion of the partition plate 8, and a front end portion of the cross member 11. It is comprised with the diagonal 12 provided so that between might be connected.
[0016]
Dampers 13 and 14 such as bellows dampers that suppress vertical vibration are provided between the tip of the damper support member 10 and the upper and lower plate members 6 and 7.
[0017]
FIG. 5 shows a bellows damper which is an example of the dampers 13 and 14. Such a bellows damper is already employed as a damping member for large-diameter pipes and devices in nuclear facilities and the like. In addition, even minute amplitude vibrations with an amplitude of 1 mm or less can be controlled, and a great damping force can be obtained by selecting a viscous fluid, a nozzle shape, or the like.
[0018]
FIG. 5 shows a bellows damper of the upper damper 13, a rod body 15 having one end fixed to the upper plate member 6, and a rod body 16 having one end fixed to the tip of the cross member 11 of the damper support member 10. Between.
[0019]
The bellows damper is provided on a pair of flanges 17, 17 fixed to the other ends of the rod bodies 15, 16, a stretchable metal bellows 18 provided on one flange 17 side, and on the other flange 17 side. And a nozzle member 19. A viscous fluid 20 is enclosed in the metal bellows 18, and when the distance between the flanges 17, 17 changes due to bending of the girder 2 due to vibration, the viscous fluid 20 is in the center of the metal bellows 18. Passing through the nozzle 19a of the nozzle member 19 located at the position, the rod bodies 15 and 16, that is, the upper plate material 6 to which the rod bodies 15 and 16 are fixed are given a damping action by the resistance at this time. Yes. Moreover, the bellows damper which is the damper 14 provided between the lower board | plate material 7 and the damper support member 10 is comprised similarly.
[0020]
The operation of the above embodiment will be described below.
[0021]
A damper support member 10 that extends in the lateral direction is fixed to an upper and lower intermediate position of the partition plate 8, and a damper that suppresses vibration in the vertical direction between the front end portion of the damper support member 10 and the upper plate member 6 and the lower plate member 7. 13 and 14, when vertical vibration is applied to the girder 2 of the overhead crane and the girder 2 bends vertically downward as shown in FIG. 3, a tensile load is applied to the damper 13 above the damper support member 10. At the same time, when a compressive load is applied to the damper 14 below the damper support member 10, and the girder 2 of the overhead crane is bent vertically upward as opposed to FIG. 3, the damper 13 above the damper support member 10 is compressed. At the same time as the load is applied, a tensile load is applied to the damper 14 below the damper support member 10. Both the compressive load and the tensile load are damped by the dampers 13 and 14. Deal of damping force is obtained, so that the vibration in the vertical direction is effectively suppressed. In the drawings, the bending of the girder 2 and the movements of the dampers 13 and 14 are exaggerated for easy understanding, but it goes without saying that the movement is actually a small movement of about several millimeters.
[0022]
Moreover, although the case where the dampers 13 and 14 are provided in two places on the right and left in the girder 2 is shown in FIG. 4, the number of installations and installation locations of dampers can be selected arbitrarily.
[0023]
As in the above-described present invention, the damper support member 10 extending in the lateral direction is fixed to the upper and lower intermediate positions of the partition plate 8, and the upper and lower plates 6 and 7 are disposed between the tip of the damper support member 10 and the upper and lower plate members 6 and 7. According to the overhead crane provided with the dampers 13 and 14 for suppressing the vibration in the direction, the operation amount of the dampers 13 and 14 when the girder 2 is bent by the vibration can be increased, and as shown in FIG. In addition to a special damper such as a bellows damper, a general damper conventionally used can also be used.
[0024]
Hereinafter, the damper operation amount δ and the damping ratio η in the vibration damping structure of the overhead crane according to the present invention will be described.
[0025]
In FIG. 6, the compressive stress σu and its deflection εu and the tensile stress σd and its deflection εd when the girder 2 is bent by vertical vibration are expressed as follows:
σu = −M / Z, εu = σu / E = −M / EZ
σd = + M / Z, εd = σd / E = + M / EZ
E: Young's modulus Z: Section modulus.
[0026]
Further, as shown in FIG. 7, the distance between the partition plate 8 to which the damper support member 10 is fixed when the girder 2 is bent by the vertical vibration and the fixing portions of the dampers 13 and 14 to the damper support member 10. The compression side distance l u, the tension side distance l d and the deflection angle θ with respect to l are:

H: Girder height dimension.
[0027]
The damper operating amount δ ₁ is

It is.
[0028]
Also, the damping ratio ζ is

Δe: Damping energy e: Total energy of vibration system C: Damper damping capacity K: Crane bending rigidity ω: Natural angular frequency m: Effective mass of crane bending vibration mode X: Crane bending amount δ ₁ : Damper operating amount.
[0029]
On the other hand, when the girder 2 is bent downward by vertical vibration as shown in FIG. 8, the distance l between the partition plates 8 and 8 changes between the upper side and the lower side. There is a method of damping by providing a damper D that suppresses a change in the horizontal distance between the lower portion and the lower portion.
[0030]
The damper operating amount δ ₂ when such a horizontal damper D is provided is:
[Equation 5]

It is.
[0031]
Accordingly, when the damper operation amount δ ₂ when the horizontal damper D is provided is compared with the damper operation amount δ ₁ of the dampers 13 and 14 shown in FIG.

It becomes.
[0032]
Normally, the distance l between the partition plates is larger than the height dimension H of the girder 2, and H <l. Therefore, the damper operation amount is larger in the present invention.
[0033]
As described above, when the damper operation amount is large, the vibration damping effect by the dampers 13 and 14 can be easily increased. Therefore, a damper that has been conventionally used is used without using a special damper. However, a large damping force is obtained, and vertical vibration can be effectively suppressed.
[0034]
The present invention is not limited only to the above-described embodiments. The shape of the damper support member can be variously changed, various dampers can be used, and other various modifications can be made without departing from the scope of the present invention. Of course, it can be added.
[0035]
【The invention's effect】
According to the present invention, the damper support member that extends in the lateral direction is fixed to the upper and lower intermediate positions of the partition plate, and the damper that suppresses the vibration in the vertical direction between the tip of the damper support member and the upper plate material and the lower plate material. Therefore, it is possible to increase the amount of operation of the damper when the girder bends up and down due to vertical vibrations. Therefore, the damper generally used from the past can be used without using a special damper. Even if it is used, a large damping force can be obtained, and there is an effect that it is possible to provide a vibration control structure for an overhead crane with high vibration resistance and high reliability in a vertical direction with a small device at a low cost.
[Brief description of the drawings]
FIG. 1 is a front view showing an example of a form of a vibration damping structure for an overhead crane according to the present invention.
2 is an enlarged front view showing a part of the girder of FIG. 1; FIG.
FIG. 3 is a front view showing a state where the girder of FIG. 2 is bent.
4 is an enlarged view in the IV-IV direction of FIG.
FIG. 5 is a front view showing an example of a damper.
FIG. 6 is a diagram for explaining stress and deflection of a bent girder.
FIG. 7 is a diagram for explaining a damper operation amount of the present invention.
FIG. 8 is a front view for explaining a damper operation amount in a damper installation method different from the present invention.
FIG. 9 is a front view showing an example of a conventional vibration damping structure of an overhead crane.
FIG. 10 is a front view showing a state where a girder is bent up and down by vertical vibration.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Rail 2 Girder 6 Upper plate material 7 Lower plate material 8 Partition plate 9 Vertical beam 10 Damper support member 11 Cross member 12 Diagonal material 13 Damper 14 Damper

Claims (2)

A plurality of partition plates that divide the interior along the length direction in an internal hollow girder having an upper plate member, a lower plate member, and left and right vertical beams that are freely run between rails fixed to the ceiling. In the overhead crane provided, a damper support member that extends in the lateral direction is fixed to an upper and lower intermediate position of the partition plate, and a damper that suppresses vibration in the vertical direction is provided between the tip of the damper support member and the upper plate material and the lower plate material. A vibration control structure for an overhead crane, characterized by comprising. The damper support member is composed of a cross member that extends in a lateral direction from an upper and lower intermediate position of the partition plate, and a diagonal member that connects between the upper end portion and the lower end portion of the partition plate and the front end portion of the cross member. The vibration damping structure for an overhead crane according to claim 1.

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