JP2011213455A - Quay crane - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a quay crane having a vibration damping structure for restraining horizontal vibration (vibration in the traverse direction and vibration in the travel direction) and torsional vibration (vertical torsional vibration and horizontal torsional vibration) generated in the quay crane.SOLUTION: This quay crane 1 includes a travel device 30 under a leg structure 2, and has a girder 3 and a boom 4 above. In the quay crane 1, at least one vibration damping device 5 is respectively arranged on the girder 3 and the boom 4, and the vibration damping device 5 has a vibration damping mass m rockably arranged via a damping mechanism 7 to the girder 3 or the boom 4.

Description

  The present invention relates to a quay crane in which a crane or the like used for container handling at a port or an inland container terminal is provided with an earthquake countermeasure.

  Container terminals such as harbors and inland areas handle containers between ships and trailers by quay cranes, portal cranes, and container trailers. As a countermeasure against earthquakes in this container terminal, a crane has been proposed in which a machine room of a quay crane is used as a damping mass (weight) to obtain a damping effect (see, for example, Patent Document 1).

  Fig. 5 shows an example of a quay crane with conventional earthquake countermeasures. The quay crane 1X has a traveling device 30 via a seismic isolation device (isolator) 13 at the lower end of the leg structure 2, and has a girder 3 and a boom 4 above. The leg structure 2 includes a sea-side and land-side leg 20 and a leg connecting structure 21 that connects the legs 20 to each other.

  Further, the trolley 31 travels along the girder 3 and the boom 4 and is configured to carry out container handling work. The traveling device 30 has wheels that travel on rails laid on the quay (the ground surface 12). The seismic isolation device 13 is a device for insulating the crane 1X from the vibration of the ground surface 12, and uses, for example, an isolator in which steel plates and rubber are alternately laminated.

  Further, the crane 1 </ b> X has a vibration damping device 5 </ b> X using the machine room 6 on the girder 3. The vibration damping device 5X is configured such that wheels 33 are installed on the lower surface of the machine room 6 so that the machine room 6 can move on the girder 3 in the sea-land direction. The x-axis indicates the sea-land direction (crane traverse direction), the y-axis indicates the direction along the quay (crane travel direction), and the z-axis indicates the vertical direction.

  Next, the crane 1X modeled for vibration analysis shown in FIG. 6 will be described. This vibration analysis model shows the relationship between the crane mass point M, which is the center of gravity of the crane 1X (mass body), and the damping mass mx (machine room 6). The crane mass point M is installed on the ground surface 12 via the seismic isolation device 13 modeled by the spring mechanism 9 and the damper mechanism 10. Similarly, the damping mass mx is installed in the girder 3 via the damping mechanism 7 modeled by the spring mechanism 9 and the damper mechanism 10.

  Next, the operation of the crane 1X when an earthquake occurs will be described. When an earthquake occurs, the shear pin or the like that has fixed the seismic isolation device 13 breaks, and the seismic isolation device 13 operates. The seismic isolation device 13 insulates the crane structure from the vibration of the ground surface 12 and suppresses the vibration of the crane-structure in the sea-land direction vibration S1 indicated by the arrow. With this structure, the crane 1X can obtain a seismic isolation effect.

  Further, when an earthquake occurs, the shear pin or the like that has fixed the machine room 6 is broken, and the vibration damping device 5X is activated. The vibration damping device 5X is configured such that the machine room 6 can swing with respect to the crane 1X. The machine room 6 vibrates in the sea-land direction (x-axis direction) with a phase opposite to that of the crane 1X.

Further, the relative motion between the machine room 6 and the crane 1X is damped by a damping mechanism 7 (for example, a combination of a spring mechanism and a damper mechanism) installed between the machine room 6 and the crane 1X. That is, the machine room 6 is configured to be used as a damping mass (a damping weight).

  The vibration control device is a technology currently used in high-rise buildings, etc., and consists of several tens to several hundred tons of weight (vibration control mass) that can be swung freely on the rooftop of a building. is doing. When an earthquake occurs, the vibration of the building is in the same vibration mode as a beam with one end fixed (ground surface side) and the other open (top side). Therefore, the vibration of the building can be reduced due to the presence of the damping mass that vibrates in the opposite phase to the vibration of the building.

  The crane 1X can suppress and attenuate the vibration in the sea-land direction (x-axis direction) by the above-described seismic isolation device 13 and the vibration control device 5X. In addition, the vibration in the direction along the quay (y-axis direction) can be absorbed because the metal wheel installed on the traveling device 30 rolls or slides on the metal rail. That is, the quay crane 1X can suppress and dampen vibrations in two directions, ie, the sea-land direction (x-axis direction) and the direction along the quay (y-axis direction).

  However, the crane 1X having the above-described configuration has the following problems. 1stly, the crane 1X has the problem that the longitudinal torsional vibration w1 which moves up and down alternately the edge part of the girder 3 and the boom 4 cannot be suppressed. That is, the rotation around the center axis in the direction along the quay (y-axis) cannot be suppressed.

  The longitudinal torsional vibration w1 causes an accident that the sea side and land side wheels of the crane float alternately and the wheels derail from the rail. Due to the occurrence of this accident, it took a long time to restore the crane after the earthquake.

  Secondly, the crane 1X has a problem that the lateral torsional vibration w2 in which the girder 3 and the boom 4 rotate in a horizontal plane cannot be suppressed. That is, it is not possible to suppress rotation about the vertical direction (z axis) as the central axis.

  These problems occur because important objects such as the girder 3 and the boom 4 are arranged far from the center of gravity in the main structure of the crane. In other words, in a beam-like high-rise building or the like, it was possible to dampen the vibration of the building by installing a damping mass on a vertical line passing through the center of gravity of the entire building. However, since the crane, which is a complex-shaped structure, vibrates in a complicated manner, it is difficult to attenuate all the vibrations with a single damping mass. In addition, the crane often has no space for installing a large damping mass on a vertical line passing through the center of gravity of the entire crane.

JP 2009-244202 A

  The present invention has been made in view of the above problems, and its purpose is to suppress horizontal vibration (transverse direction vibration and traveling direction vibration) and torsional vibration (longitudinal torsional vibration and lateral torsional vibration) generated in a quay crane. An object of the present invention is to provide a quay crane having a vibration control structure.

In order to achieve the above object, a quay crane according to the present invention is a quay crane having a traveling device below a leg structure and having a girder and a boom above, and each of the girder and the boom has at least one. A damping device is installed, and the damping device has a damping mass that is swingably installed with respect to the girder or the boom via a damping mechanism.

  With this configuration, since the damping mass is arranged at at least two positions away from the center of gravity of the crane located inside the leg structure, the vertical and horizontal torsional vibrations of the crane are suppressed and attenuated. be able to. At the same time, horizontal vibrations of the crane can be suppressed and damped.

  In the above quay crane, at least one vibration damping device is installed on the leg constituting the leg structure and the leg joint structure connecting the leg to each other, and the vibration damping device is the leg or the leg joint. It has the damping mass installed so that rocking was possible via the damping mechanism with respect to the structure.

  With this configuration, in addition to the girder and boom, the vibration control device is installed in the leg structure against the center of gravity of the crane located inside the leg structure, so that the torsional vibration and horizontal vibration of the crane are suppressed and attenuated. Can be improved.

  In the above quay crane, the damping mass of the damping device is configured to be swingable at least in the vertical direction. With this configuration, the vertical torsional vibration of the crane can be suppressed and attenuated.

  In the above quay crane, the damping mass of the damping device is configured to be swingable in a direction intersecting at least the longitudinal direction of the girder and the boom. With this configuration, the lateral torsional vibration of the crane can be suppressed and damped.

  In the quay crane described above, the damping mechanism includes at least a spring mechanism and a damper mechanism.

  In the above quay crane, at least one of the girder and the boom is formed of a hollow columnar structure, and at least one vibration damping device is installed inside the hollow columnar structure. With this configuration, it is possible to install the vibration control device without adding a significant design change to the conventional crane. Moreover, since the vibration damping device is not exposed to wind and rain, the effect of suppressing and attenuating the torsional vibration and horizontal vibration of the crane can be stably maintained.

  The crane according to the present invention can provide a quay crane having a vibration control structure that suppresses and attenuates torsional vibration (vertical torsional vibration and lateral torsional vibration) generated in the quay crane. Moreover, the quay crane which has the damping structure which suppresses and damps the horizontal vibration (transverse direction vibration and traveling direction vibration) which generate | occur | produces in a quay crane can be provided.

It is the figure which showed the side model for vibration analysis of the crane of embodiment which concerns on this invention. It is the figure which showed the plane model for vibration analysis of the crane of embodiment which concerns on this invention. It is the figure which showed the vibration damping device of the crane of embodiment which concerns on this invention. It is the figure which showed the model of the damping device of the crane of embodiment which concerns on this invention. It is the figure which showed the outline | summary of the side surface of the conventional crane. It is the figure which showed the side model for vibration analysis of the conventional crane.

  Hereinafter, a crane according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a side model for vibration analysis of a crane 1 having a plurality of vibration control devices 5. The crane 1 has vibration control devices 5 installed on the girder 3 and the boom 4 (also referred to as a crane structure). The damping device 5 is configured by installing a first damping mass m1 and a second damping mass m2 (hereinafter collectively referred to as a damping mass m) on a structure via a damping mechanism 7, respectively. . The damping mass m is installed so as to be swingable at least in the vertical direction (z-axis direction) with respect to the girder 3 and the boom 4 by the damping mechanism 7.

The damping mechanism 7 needs to have a structure in which the damping mass m is movable in the vertical direction (z-axis direction) and the relative motion between the damping mass m and the crane structure is damped. For example, a combination of a spring mechanism and a damper mechanism, an isolator configured by stacking steel plates and rubber, or the like can be used. In FIG. 1, the damping mechanism 7 is shown as a model by a spring mechanism and a damper mechanism. The crane 1 also has a seismic isolation device 13 between the ground surface 12 and the crane 1. This seismic isolation device 13 is also shown as a model with a spring mechanism and a damper mechanism. The center of gravity of the crane 1 is indicated by a crane mass point M, the x-axis direction indicates the sea-land direction, and the z-axis direction indicates the vertical direction.

  Next, the operation of the crane 1 when an earthquake occurs will be described. When the vertical torsional vibration w1 occurs in the crane 1 due to the occurrence of the earthquake, both ends of the girder 3 and the boom 4 move up and down as indicated by broken lines. With respect to the longitudinal torsional vibration w1 of the girder 3 and the boom 4, the damping mass m vibrates in an opposite phase.

  For the land-and-land direction vibration S1 in the sea-and-land direction (x-axis direction) of the crane 1, the seismic isolation device 13 that is normally fixed is opened, the ground surface 12 and the crane structure are insulated, Control is performed so that the vibration of 12 is not transmitted to the crane 1.

  With the above configuration, the longitudinal torsional vibration w1 can be suppressed and attenuated. This is because the damping mass m vibrates in the opposite phase with respect to the longitudinal torsional vibration w1 of the girder 3 and the boom 4, and the entire crane is hardly in resonance with the earthquake motion. By suppressing and attenuating the longitudinal torsional vibration w1, it is possible to prevent an accident in which the wheels of the traveling device 30 of the crane 1 are lifted and derailed when an earthquake occurs. As a result, the crane can be easily restored after the earthquake, and the cargo handling operation can be resumed quickly.

  In addition, the vibration which the damping device 5 suppresses and attenuates is effective not only in the earthquake motion but also in the vibration of the crane generated during the cargo handling work such as a container. That is, the vibration of the girder 3 and the boom 4 generated during the cargo handling operation can be significantly suppressed as compared with the conventional quay crane, and accordingly, the operability of the crane 1 can be improved.

  Further, it is desirable that the damping mass m is installed at a location near the ends of the girder 3 and the boom 4. This is because when the damping mass m is installed at the ends of the girder 3 and the boom 4, the moment generated by the movement of the damping mass m increases, and the effect of suppressing and attenuating the longitudinal torsional vibration w1 increases. is there. Therefore, it is desirable to install the damping mass m at a position away from the crane mass point M.

  Furthermore, it is possible to install three or more damping devices 5 on the girder 3 and the boom 4 to enhance the damping effect. At this time, the mass of each damping mass m, the spring constant of the spring mechanism, and the viscosity coefficient of the damper mechanism can be changed so that the crane 1 does not enter a resonance state even with a long-period earthquake motion.

  FIG. 2 shows a plane model for vibration analysis of the crane 1 shown in FIG. The damping mass m is installed by the damping mechanism 7 so as to be swingable at least in the direction along the quay (y-axis direction) with respect to the girder 3 and the boom 4.

  Next, the operation of the crane 1 when an earthquake occurs will be described. When lateral torsional vibration w2 occurs in the crane 1 due to the occurrence of the earthquake, both ends of the girder 3 and the boom 4 vibrate as indicated by broken lines. With respect to the lateral torsional vibration w2 of the girder 3 and the boom 4, the damping mass m vibrates in an opposite phase.

  With the above configuration, the lateral torsional vibration w2 can be suppressed and damped. This is because the damping mass m can be prevented from resonating with the crane as a whole with respect to the lateral torsional vibration w <b> 2 of the girder 3 and the boom 4.

  From the above, in at least two damping devices 5, if the damping mass m can swing in the vertical direction (z-axis direction), the longitudinal torsional vibration w1 is indicated, and the damping mass m is in the direction along the quay (y-axis). The lateral torsional vibration w2 can be suppressed and damped if it can be swung in the direction). Furthermore, the damping mass m can be swung in the sea-land direction (x-axis direction), and the sea-land direction vibration S1 can be suppressed and attenuated.

  FIG. 3 shows an outline of an example of the vibration damping device 5. The damping device 5 has a damping mass m provided inside a girder 3, a boom 4, a leg 20, or a leg connecting structure 21 that is a hollow columnar structure via a damping mechanism 7 (for example, a spring damper 17). It has an installed configuration.

The damping mass m is installed on the y-axis direction carriage 14y via a spring damper 17z. The damping mass m is configured to slide in a hole 19 formed in the y-axis direction carriage 14y. It is configured to be swingable in the z-axis direction. The y-axis trolley 14y is configured to be able to travel on wheels 16y on a rail 16y installed on the x-axis trolley 14x. Further, the y-axis direction carriage 14y is connected to the x-axis direction carriage 14x via a spring damper 17y. That is, it is configured to be swingable in the y-axis direction. The x-axis trolley 14X is configured to be able to run on wheels 16x on rails 16x formed on the inner wall 11 of the columnar structure. Further, the x-axis direction carriage 14x is connected to the inner wall 11 via a spring damper 17x. That is, it is configured to be swingable in the x-axis direction.

  The vibration damping device 5 is configured to vibrate in all directions by virtue of a structure in which the damping mass m swings in the z-axis direction, the y-axis cart 14y swings in the y-axis direction, and the x-axis cart 14x swings in the x-axis direction. In contrast, a vibration control effect can be obtained. Further, the masses of the x-axis direction carriage 14x and the y-axis direction carriage 14y can be used as the damping mass. In this case, the strongest vibration damping effect can be obtained in the x-axis direction. Therefore, when installing in the girder 3 etc., it is desirable to install the damping device 5 so that the transverse direction with large vibration and the swing direction of the x-axis direction carriage 14x coincide.

  The vibration damping device 5 can also be installed on the surface of the crane structure. For example, it can be installed on the upper surface side of the girder or boom, or can be installed so as to be hung on the lower surface side. Moreover, it can also install in the side surface of a leg or a leg connection structure. At this time, the direction in which the vibration damping device can swing may be selected depending on the installation location of the vibration damping device. That is, for example, the vibration control device installed on the side surface of the leg may be configured to be able to swing in the x-axis direction and the y-axis direction and not swing in the z-axis direction.

FIG. 4 shows a model of the vibration damping device 5. The damping device 5 includes a damping mass m, an inner wall 11 of the girder 3 or the boom 4, and a damping mechanism 7 that connects the damping mass m and the inner wall 11. The damping mechanism 7 is shown as a combination of a spring mechanism 9 and a damper mechanism 10.

  Further, it is desirable that the different attenuation mechanisms 7 in the axial direction are respectively installed via the frame 18. With the configuration using the frame 18, vibrations in the x-axis, y-axis, z-axis, and other directions can be damped independently. Note that the vibration damping device 5 shown in FIG. 3 employs a multi-frame structure and is configured to independently attenuate vibrations in the x-axis, y-axis, and z-axis directions.

  Next, the operation of the vibration damping device 5 will be described. The vibration damping device 5 is configured such that the vibration damping mass m can swing in a direction along the quay (y-axis direction) and in a vertical direction (z-axis direction). The natural frequency of the damping mass m can be arbitrarily determined using the mass of the damping mass m, the spring constant k of the spring mechanism 9 and the viscosity coefficient c of the damper mechanism 10 as parameters.

  With the above-described configuration, the vibration damping device 5 can be designed so as to obtain an optimum vibration damping effect with respect to a presumed period of earthquake motion. That is, the longitudinal torsional vibration w1 and the lateral torsional vibration w2 can be estimated in advance from the shape of the crane 1 and the assumed period of earthquake motion. With respect to the estimated torsional vibration, the optimum parameters of the vibration damping device 5 can be determined at the design stage of the crane 1.

  From the above, it is possible to provide the quay crane 1 that can suppress and attenuate the longitudinal torsional vibration w1 and the lateral torsional vibration w2 and obtain a high vibration damping effect. The present invention is not limited to a quay crane, and can be similarly applied to a crane having a long boom such as a jib crane.

1 Crane (quay crane)
2 leg structure 3 girder 4 boom 5 damping device 7 damping mechanism 9 spring mechanism 10 damper mechanism 11 inner wall m damping mass m1 first damping mass m2 second damping mass M crane center of gravity mass w torsional vibration w1 longitudinal torsional vibration w2 Lateral torsional vibration

Claims (6)

In a quay crane having a traveling device below the leg structure and having a girder and a boom above,
At least one damping device is installed on each of the girder and the boom,
The quay crane, wherein the vibration control device has a vibration control mass that is swingably installed with respect to the girder or the boom via a damping mechanism. Installing at least one vibration control device on a leg constituting the leg structure and a leg connecting structure connecting the leg and the leg;
The quay crane according to claim 1, wherein the vibration control device includes a vibration control mass that is swingably installed on the leg or the leg connecting structure via a damping mechanism.   The quay crane according to claim 1 or 2, wherein the damping mass of the damping device is configured to be swingable at least in a vertical direction.   4. The damping mass of the damping device is configured to be swingable in a direction that intersects at least the longitudinal direction of the girder and the boom. Quay crane.   The quay crane according to any one of claims 1 to 4, wherein the damping mechanism includes at least a spring mechanism and a damper mechanism.   6. At least one of the girder and the boom is constituted by a hollow columnar structure, and at least one vibration damping device is installed inside the hollow columnar structure. The quay crane according to item 1.

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